MAX9888EVKIT+ - Maxim Integrated

_______________________________________________________________ Maxim Integrated Products 1

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

Stereo Audio CODEC

with FlexSound Technology

MAX9888

19-5235; Rev 1; 2/11

Simplified Block Diagram

General Description

The MAX9888 is a full-featured audio CODEC whose

high performance and low power consumption make it

ideal for portable applications.

Class D speaker amplifiers provide efficient amplification

for two speakers. Low radiated emissions enable com-

pletely filterless operation. Integrated bypass switches

optionally connect an external amplifier to the transducer

when the Class D amplifiers are disabled.

DirectDrive® headphone amplifiers provide a true

ground-referenced output, eliminating the need for

large DC-blocking capacitors. 1.8V headphone opera-

tion ensures low power consumption. The device also

includes a differential receiver amplifier.

Three differential analog microphone inputs are available

as well as support for two PDM digital microphones.

Integrated switches allow microphone signals to be

routed out to external devices. Two flexible single-ended

or differential line inputs may be connected to an FM

radio or other sources.

Integrated FlexSoundK technology improves loud-

speaker performance by optimizing the signal level and

frequency response while limiting the maximum distor-

tion and power at the output to prevent speaker damage.

Automatic gain control (AGC) and a noise gate optimize

the signal level of microphone input signals to make best

use of the ADC dynamic range.

The device is fully specified over the -40NC to +85NC

extended temperature range.

Features

S 100dB DR Stereo DAC (8kHz < fS < 96kHz)

S 91dB DR Stereo ADC (8kHz < fS < 96kHz)

S Stereo Low EMI Class D Amplifiers

950mW/Channel (8I, VSPKVDD_ = 4.2V)

S Stereo DirectDrive Headphone Amplifiers

S Differential Receiver Amplifier

S 2 Stereo Single-Ended/Mono Differential Line

Inputs

S 3 Differential Microphone Inputs

S FlexSound Technology

5-Band Parametric EQ

Automatic Level Control (ALC)

Excursion Limiter

Speaker Power Limiter

Speaker Distortion Limiter

Microphone Automatic Gain Control

and Noise Gate

S Dual I2S/PCM/TDM Digital Audio Interfaces

S Asynchronous Digital Mixing

S Supports Master Clock Frequencies from 10MHz

to 60MHz

S RF Immune Analog Inputs and Outputs

S Extensive Click-and-Pop Reduction Circuitry

S I2C Control Interface

S 63 WLP Package (3.80mm x 3.30mm, 0.4mm Pitch)

+Denotes lead(Pb)-free/RoHS-compliant package.

Ordering Information

DirectDrive is a registered trademark and FlexSound is a

trademark of Maxim Integrated Products, Inc.

PART TEMP RANGE PIN-PACKAGE

MAX9888EWY+ -40NC to +85NC63 WLP

DAC

MIX

RECEIVER AMP

SPEAKER AMP

HEADPHONE AMP

ADC

MIX

FlexSound TECHNOLOGY

• 5-BAND PARAMETRIC EQ

• AUTOMATIC LEVEL CONTROL

• LOUDSPEAKER PROCESSING

• EXCURSION LIMITER

• THD LIMITER

• POWER LIMITER

• MICROPHONE PROCESSING

• AUTOMATIC GAIN CONTROL

• NOISE GATE

• ASYNCHRONOUS DIGITAL

MIXING

DIGITAL MICROPHONE

INPUT

I2C

CONTROL

I2S/PCM

DIGITAL

AUDIO

INTERFACE

I2S/PCM

DIGITAL

AUDIO

INTERFACE

LINEIN A1

LINEIN A2

LINEIN B1

LINEIN B2

MAX9888

Stereo Audio CODEC

with FlexSound Technology

MAX9888

TABLE OF CONTENTS

General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Features ..................................................................................... 1

Simplified Block Diagram ........................................................................ 1

Ordering Information ........................................................................... 1

Functional Diagram ............................................................................ 5

Absolute Maximum Ratings ...................................................................... 6

Electrical Characteristics ........................................................................ 6

Digital Input/Output Characteristics ............................................................... 19

Input Clock Characteristics ..................................................................... 21

Audio Interface Timing Characteristics ............................................................ 22

Digital Microphone Timing Characterstics .......................................................... 23

I2C Timing Characterstics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Power Consumption ........................................................................... 25

Typical Operating Characteristics ................................................................ 28

Microphone to ADC..........................................................................28

Line to ADC................................................................................32

Digital Loopback ............................................................................33

Analog Loopback ...........................................................................34

DAC to Receiver ............................................................................35

Line to Receiver ............................................................................37

DAC to Speaker.............................................................................38

Line to Speaker .............................................................................42

DAC to Headphone..........................................................................43

Line to Headphone ..........................................................................48

Speaker Bypass Switch ......................................................................49

Pin Configuration ............................................................................. 50

Pin Description ............................................................................... 51

Detailed Description........................................................................... 53

I2C Slave Address...........................................................................54

Registers ..................................................................................54

Power Management .........................................................................59

Microphone Inputs ..........................................................................60

Line Inputs.................................................................................62

ADC Input Mixers ...........................................................................63

Record Path Signal Processing.................................................................64

Microphone AGC .........................................................................64

Noise Gate ..............................................................................64

Stereo Audio CODEC

with FlexSound Technology

MAX9888

TABLE OF CONTENTS (continued)

ADC Record Level Control ....................................................................67

Sidetone ..................................................................................68

Digital Audio Interfaces .......................................................................69

Clock Control...............................................................................76

Passband Filtering...........................................................................78

Playback Path Signal Processing ...............................................................81

Automatic Level Control ....................................................................81

Parametric Equalizer ......................................................................82

Playback Level Control .......................................................................84

DAC Input Mixers ...........................................................................85

Preoutput Signal Path ........................................................................86

Preoutput Mixer ..........................................................................86

Preoutput PGA ...........................................................................87

Receiver Amplifier ...........................................................................87

Receiver Output Volume ...................................................................88

Receiver Output Mixer .....................................................................88

Speaker Amplifiers ..........................................................................89

Speaker Output Volume ....................................................................90

Speaker Output Mixers ....................................................................90

Speaker Amplifier Signal Processing ............................................................91

Excursion Limiter .........................................................................91

Power Limiter ............................................................................93

Distortion Limiter .........................................................................94

Headphone Amplifier ........................................................................95

Headphone Output Mixers..................................................................96

Headphone Output Volume .................................................................97

Output Bypass Switches ......................................................................98

Click-and-Pop Reduction .....................................................................99

Jack Detection.............................................................................100

Jack Insertion...........................................................................100

Accessory Button Detection ...............................................................100

Jack Removal...........................................................................101

Stereo Audio CODEC

with FlexSound Technology

MAX9888

TABLE OF CONTENTS (continued)

Battery Measurement .......................................................................102

Device Status .............................................................................103

Device Revision............................................................................104

I2C Serial Interface .........................................................................104

Bit Transfer .............................................................................104

START and STOP Conditions...............................................................104

Early STOP Conditions....................................................................104

Slave Address ..........................................................................105

Acknowledge ...........................................................................105

Write Data Format .......................................................................105

Read Data Format .......................................................................106

Applications Information....................................................................... 107

Typical Operating Circuits ....................................................................107

Analog Microphones and Bypass Switch .....................................................107

Digital Microphones and Receiver Amplifier ...................................................108

Filterless Class D Operation ..................................................................109

RF Susceptibility ...........................................................................109

Startup/Shutdown Sequencing ................................................................109

Component Selection .......................................................................110

Optional Ferrite Bead Filter ................................................................110

Input Capacitor..........................................................................110

Charge-Pump Capacitor Selection ..........................................................110

Charge-Pump Flying Capacitor .............................................................111

Charge-Pump Holding Capacitor ...........................................................111

Unused Pins ..............................................................................111

Recommended PCB Routing .................................................................112

Supply Bypassing, Layout, and Grounding ......................................................112

WLP Applications Information .................................................................113

Package Information...........................................................................114

Revision History ..............................................................................115

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Functional Diagram

SDA SCL

I2C

E5F5F4 E2

MCLK

CLOCK

CONTROL

INBDIFF

MIXOUT3

MIXOUT2

PGAINB:

+20dB TO -6dB

C8 INB2

D8 INB1

D9 INA2/EXTMICN

E9 INA1/EXTMICP

G9 MIC2N

F9 MIC2P

D6 JACKSNS JACK

DETECTION

JDETEN

MBEN

G8 MICBIAS REG

MIX

PGAINB:

+20dB TO -6dB

INADIFF

INABYP

MIC2BYP

PGAINA:

+20dB TO -6dB

PGAOUT1:

0dB TO -23dB

PGAOUT2:

0dB TO -23dB

PGAOUT3:

0dB TO -23dB

PGAINA:

+20dB TO -6dB

PGAM2:

+20dB TO 0dB

PGAM1:

+20dB TO 0dB

MIXOUT1

PREOUT1

MIX

MIXADR

ADREN

ADLEN

PSCLK

MIX

MIXADL

MIX

PA2EN:

0/20/30dB

EXTMIC

PA1EN:

0/20/30dB

EXTMIC

MIC1N/

DIGMICCLK

MIC1P/

DIGMICDATA

ADCR

ADCL

PREOUT2

PREOUT3

+9dB

AVLG: 0/6/12/18dB

AVL: 3dB TO -12dB

MODE1

AVFLT

DSTS

MAS1

DAI1

SEL1 SEL2

BCLK1

BCLKS1

D1 D2 E4 D4 E1 F2 F3 G1 G3 G2

LRCLK1

SDOUT1

SDIN1

SIDETONE

DVST:

0dB TO -60dB

LTEN1

LBEN2

AVRG: 0/6/12/18dB

AVR: 3dB TO -2dB

AUTOMATIC

GAIN

CONTROL

EQ1EN EQ2EN

DVEQ1:

0dB TO -15dB

DV1G:

0/6/12/18dB

DV2:

0dB TO -15dB DCB2

5-BAND

PARAMETRIC

5-BAND

PARAMETRIC

DVEQ2:

0dB TO -15dB

FlexSound

TECHNOLOGY

MULTI BAND ALC

EXCURSION LIMITER

DV1:

0dB TO -15dB MODE1

DVFLT

DALEN

MIXDAR

DACL

DAREN

DACR

BIT

CLOCK

FRAME

CLOCK

DATA

OUTPUT

DATA

INPUT

MAS1 HIZOFF1 MAS2

DAI2

BCLK2

LRCLK2

SDOUT2

SDIN2

BIT

CLOCK

FRAME

CLOCK

DATA

OUTPUT

DATA

INPUT

MAS2 HIZOFF2

LRCLKS1 SDOUTS1 SDINS1 DVDDS1 BCLKS2 LRCLKS2 SDOUTS2 SDINS2 DVDDS2

DVDD

AVDD

MUX

LBEN1

MIXREC

BATTERY ADC

0dB

RECVOL:

+8dB TO -62dB

RECP/

RXINP A6

RECN/

RXINN

SPKLP

SPKLN

RECBYP

SPKBYP

RECEN

MIXSPL

+6dB

SPVOLL:

+8dB TO -62dB A4, B4

SPKLVDD A3, B3

A5, B5

SPKLGND C4, C5

SPKRVDD C3, D3

SPKRP C1, C2

SPKRN A1, B1

SPLEN

SPREN

POWER/

DISTORTION LIMITER

MIXSPR

+6dB

SPVOLR:

+8dB TO -62dB

HPVOLL:

+3dB TO -67dB

SPKRGND A2, B2

HPL B9

HPSNS C6

HPR C9

HPLEN

MIXHPL

HPVOLR:

+3dB TO -67dB

HPVDD A7

HPGND A8

B7B8A9G7F1

HPREN

MIXHPR

HPVSSAGND

DGND C1N C1P

CHARGE

PUMP

REF F7

PREG

REG

BIAS

MAX9888

NOISE GATE

AUDIO/

VOICE

FILTERS

AUDIO/

FILTERS

AUDIO/

VOICE

FILTERS

MIX

MIXDAL

MIX

IRQ

PORT S1 PORT S2

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute

maximum rating conditions for extended periods may affect device reliability.

(Voltages with respect to AGND.)

DVDD, AVDD, HPVDD .........................................-0.3V to +2.2V

SPKLVDD, SPKRVDD, DVDDS1, DVDDS2 ..........-0.3V to +6.0V

DGND, HPGND, SPKLGND, SPKRGND ..............-0.1V to +0.1V

HPVSS ............................... (HPGND - 2.2V) to (HPGND + 0.3V)

C1N .................................... (HPVSS - 0.3V) to (HPGND + 0.3V)

C1P .....................................(HPGND - 0.3V) to (HPVDD + 0.3V)

PREG ..................................................... -0.3V to (AVDD + 0.3V)

REF, MICBIAS ................................. -0.3V to (SPKLVDD + 0.3V)

MCLK, SDINS1, SDINS2, JACKSNS,

SDA, SCL, IRQ .................................................-0.3V to +6.0V

LRCLKS1, BCLKS1, SDOUTS1 ......... -0.3V to (DVDDS1 + 0.3V)

LRCLKS2, BCLKS2, SDOUTS2 ......... -0.3V to (DVDDS2 + 0.3V)

REG, INA1, INA2, INB1, INB2, MIC1P/DIGMICDATA,

MIC1N/DIGMICCLK, MIC2P, MIC2N ...............-0.3V to +2.2V

HPSNS ............................... (HPGND - 0.3V) to (HPGND + 0.3V)

HPL, HPR ............................ (HPVSS - 0.3V) to (HPVDD + 0.3V)

RECP, RECN ..............(SPKLGND - 0.3V) to (SPKLVDD + 0.3V)

SPKLP, SPKLN ...........(SPKLGND - 0.3V) to (SPKLVDD + 0.3V)

SPKRP, SPKRN .........(SPKRGND - 0.3V) to (SPKRVDD + 0.3V)

Continuous Power Dissipation (TA = +70NC)

63-Bump WLP (derate 25.6mW/NC above +70NC) ........2.05W

Operating Temperature Range .......................... -40NC to +85NC

Storage Temperature Range ............................ -65NC to +150NC

Soldering Temperature (reflow) ......................................+260NC

ELECTRICAL CHARACTERISTICS

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

ABSOLUTE MAXIMUM RATINGS

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER SUPPLY

Supply Voltage Range Guaranteed by PSRR

VSPKLVDD,

VSPKRVDD 2.8 5.5

VDVDD, VAVDD,

VHPVDD 1.65 1.8 2.0

VDVDDS1,

VDVDDS2 1.65 3.6

Total Supply Current (Note 2) IVDD

Full-duplex 8kHz mono,

receiver output (Note 3)

Analog 6.37 10

Speaker 1.98 3.5

Digital 1.49 3

DAC playback 48kHz stereo,

headphone outputs (Note 3)

Analog 2.71 4

Speaker 1.65 2.5

Digital 2.93 4.5

DAC playback 48kHz stereo,

speaker outputs (Note 3)

Analog 1.85 3

Speaker 8.22 18

Digital 2.94 5

Full-duplex 48kHz stereo,

microphone inputs,

headphone outputs (Note 3)

Analog 12.75 18

Speaker 1.7 3

Digital 3.75 5.5

Stereo line playback,

IN_DIF = 0, INA1 to HPL,

INA2 to HPR, VMCLK = 0V

Analog 5.11 7

Speaker 0.58 1

Digital 0.03 0.06

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Shutdown Supply Current

(Note 2) TA = +25NC

Analog 0.2 2

Speaker 0.1 1

Digital 1 5

REF Voltage 2.5 V

PREG Voltage 1.6 V

REG Voltage 0.7 V

Shutdown to Full Operation SLEW = 0 30 ms

SLEW = 1 17

MICROPHONE TO ADC PATH

Dynamic Range (Note 4) DR fS = 8kHz, MODE = 0 (IIR voice),

AVMICPRE_ = 0dB 75 88 dB

Total Harmonic Distortion +

Noise THD+N

VIN = 0.1VP-P, MCLK = 12.288MHz,

fS = 8kHz, f = 1kHz -77 -65

dBAVMICPRE_ = 0dB, VIN = 1VP-P, f = 1kHz -82

AVMICPRE_ = +30dB, VIN = 32mVP-P,

f = 1kHz -71

Common-Mode Rejection Ratio CMRR VIN = 100mVP-P, f = 217Hz 65 dB

Power-Supply Rejection Ratio PSRR

VAVDD = 1.65V to 2.0V, input referred, MIC

inputs floating 60 100

f = 217Hz, VRIPPLE = 100mVP-P, AVADC = 0dB,

input referred 100

f = 1kHz, VRIPPLE = 100mVP-P, AVADC = 0dB,

input referred 91

f = 10kHz, VRIPPLE = 100mVP-P, AVADC = 0dB,

input referred 70

Path Phase Delay

1kHz, 0dB input,

highpass filter

disabled measured

from analog input to

digital output

MODE = 0 (IIR voice)

8kHz 2.2

MODE = 0 (IIR voice)

16kHz 1.1

MODE = 1 (FIR audio)

8kHz 4.5

MODE = 1 (FIR audio)

48kHz 0.76

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

MICROPHONE PREAMP

Full-Scale Input AVMICPRE_ = 0dB 1.05 VP-P

Preamplifier Gain AVMICPRE_ (Note 5)

PA1EN/PA2EN = 01 0

dBPA1EN/PA2EN = 10 19.5 20 20.5

PA1EN/PA2EN = 11 29.4 30 30.5

PGA Gain AVMICPGA_ (Note 5) PGAM1/PGAM2 = 0x00 19.5 20 20.5 dB

PGAM1/PGAM2 = 0x14 0

MIC Input Resistance RIN_MIC All gain settings, measured at MIC1P/MIC1N/

MIC2P/MIC2N 30 50 kI

MICROPHONE BIAS

MICBIAS Output Voltage VMICBIAS ILOAD = 1mA 2.14 2.2 2.25 V

Load Regulation ILOAD = 1mA to 2mA 0.5 11 mV

Line Regulation VSPKLVDD = 2.8V to 5.5V 100 FV

Ripple Rejection f = 217Hz, VRIPPLE (SPKLVDD) = 100mVP-P 92 dB

f = 10kHz, VRIPPLE (SPKLVDD) = 100mVP-P 83

Noise Voltage

A-weighted, f = 20Hz to 20kHz 3.8 FVRMS

P-weighted, f = 20Hz to 4kHz 2.1

f = 1kHz 33 nV/√Hz

MICROPHONE BYPASS SWITCH

On-Resistance RON IMIC1_ = 100mA, INABYP = MIC2BYP = 1,

VMIC2_ = VINA_ = (0V, VAVDD)3.5 20 I

Total Harmonic Distortion +

Noise THD+N VIN = 2VP-P, VCM = 0.9V, RL = 10kI,

f = 1kHz, INABYP = MIC2BYP = 1 -80 dB

Off-Isolation VIN = 2VP-P, VCM = 0.9V, RL = 10kI,

f = 1kHz 60 dB

Off-Leakage Current VMIC1_ = (0V, VAVDD),

VMIC2_/VINA_ = (VAVDD, 0V) -2.5 +2.5 FA

LINE INPUT TO ADC PATH

Dynamic Range (Note 4) DR fS = 48kHz, MCLK = 12.288MHz, MODE = 1

(FIR audio) 91 dB

Total Harmonic Distortion +

Noise THD+N VIN = 1VP-P, f = 1kHz -77 dB

Gain Error DC accuracy 1 5 %

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

LINE INPUT PREAMP

Full-Scale Input VIN AVPGAIN_ = 0dB 1 VP-P

AVPGAIN_ = -6dB 1.4

Level Adjust Gain AVPGAIN_

PGAINA/PGAINB = 0x0 19 20 21

PGAINA/PGAINB = 0x1 13 14 15

PGAINA/PGAINB = 0x2 (Note 5) 2 3 4

PGAINA/PGAINB = 0x3 TA = +25NC0

PGAINA/PGAINB = 0x4 -4 -3 -2

PGAINA/PGAINB = 0x5, 0x6, 0x7 -7 -6 -5

Input Resistance RIN

AVPGAIN_ = +20dB 14.6 21 27.4

AVPGAIN_ = +14dB 20

AVPGAIN_ = +3dB 20

AVPGAIN_ = 0dB 7.3 10 13.7

AVPGAIN_ = -3dB 20

AVPGAIN_ = -6dB 20

Feedback Resistance RIN_FB INAEXT/INBEXT = 1 TA = +25NC18.5 20 21.5 kI

TA = TMIN to TMAX 17.5 23

ADC LEVEL CONTROL

ADC Level Adjust Range AVADCLVL AVL/AVR = 0xF to 0x0 (Note 5) -12 +3 dB

ADC Level Adjust Step Size 1 dB

ADC Gain Adjust Range AVADCGAIN AVLG/AVRG = 00 to 11 (Note 5) 0 18 dB

ADC Gain Adjust Step Size 6 dB

ADC DIGITAL FILTERS

VOICE MODE IIR LOWPASS FILTER (MODE1 = 0)

Passband Cutoff fPLP

Ripple limit cutoff 0.441

x fsHz

-3dB cutoff 0.449

x fs

Passband Ripple f < fPLP -0.1 +0.1 dB

Stopband Cutoff fSLP 0.47

x fsHz

Stopband Attenuation (Note 6) f > fSLP 74 dB

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

VOICE MODE IIR HIGHPASS FILTER (MODE1 = 0)

Passband Cutoff

(-3dB from Peak) fAHPPB

AVFLT = 0x1 (elliptical tuned for

fs = 16kHz + 217Hz notch)

0.0161

x fs

AVFLT = 0x2 (500Hz Butterworth tuned for

fs = 16kHz)

0.0319

x fs

AVFLT = 0x3 (elliptical tuned for

fs = 8kHz + 217Hz notch)

0.0321

x fs

AVFLT = 0x4 (500Hz Butterworth tuned for

fs = 8kHz)

0.0632

x fs

AVFLT = 0x5 (fs/240 Butterworth) 0.0043

x fs

Stopband Cutoff

(-30dB from Peak) fAHPSB

AVFLT = 0x1 (elliptical tuned for

fs = 16kHz + 217Hz notch)

0.0139

x fs

AVFLT = 0x2 (500Hz Butterworth tuned for

fs = 16kHz)

0.0156

x fs

AVFLT = 0x3 (elliptical tuned for

fs = 8kHz + 217Hz notch)

0.0279

x fs

AVFLT = 0x4 (500Hz Butterworth tuned for fs =

8kHz)

0.0312

x fs

AVFLT = 0x5 (fs/240 Butterworth) 0.002

x fs

DC Attenuation DCATTEN AVFLT ≠ 000 90 dB

STEREO AUDIO MODE FIR LOWPASS FILTER (MODE1 = 1, DHF1 = 0, LRCLK < 50kHz)

Passband Cutoff fPLP

Ripple limit cutoff 0.43

x fs

Hz-3dB cutoff 0.48

x fs

-6.02dB cutoff 0.5

x fs

Passband Ripple f < fPLP -0.1 +0.1 dB

Stopband Cutoff fSLP 0.58

x fsHz

Stopband Attenuation (Note 6) f < fSLP 60 dB

ADC STEREO AUDIO MODE FIR LOWPASS FILTER (MODE1 = 1, DHF1 = 1, LRCLK > 50kHz)

Passband Cutoff fPLP

Ripple limit cutoff 0.208

x fsHz

-3dB cutoff 0.28

x fs

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Passband Ripple f < fPLP -0.1 +0.1 dB

Stopband Cutoff fSLP 0.417

x fsHz

Stopband Attenuation f < fSLP 60 dB

ADC STEREO AUDIO MODE DC-BLOCKING HIGHPASS FILTER (MODE1 = 1)

Passband Cutoff

(-3dB from Peak) fAHPPB AVFLT ≠ 000 0.000125

x fs Hz

DC Attenuation DCAtten AVFLT ≠ 000 90 dB

MICROPHONE AUTOMATIC GAIN CONTROL

AGC Hold Duration AGCHLD = 01 50 ms

AGCHLD = 11 400

AGC Attack Time AGCATK = 00 2 ms

AGCATK = 11 123

AGC Release Time AGCRLS = 000 0.078 s

AGCRLS = 111 10

AGC Threshold Level AGCTH = 0x0 to 0xF -3 +18 dB

AGC Threshold Step Size 1 dB

AGC Gain (Note 5) 0 20 dB

ADC NOISE GATE

NG Threshold Level ANTH = 0x3 to 0xF, referred to 0dBFS -64 -16 dB

NG Attenuation (Note 5) 0 12 dB

ADC-TO-DAC DIGITAL SIDETONE (MODE = 0)

Sidetone Gain Adjust Range AVSTGA DVST = 0x01 -0.5 dB

DVST = 0x1F -60.5

Sidetone Gain Adjust Step Size 2 dB

Sidetone Path Phase Delay 1kHz, 0dB input, highpass

filter disabled

8kHz 2.2 ms

16kHz 1.1

ADC-TO-DAC DIGITAL LOOP-THROUGH PATH

Dynamic Range (Note 4) DR fS = 48kHz, MCLK = 12.288MHz, MODE = 1

(FIR audio) 89 dB

Total Harmonic Distortion THD f = 1kHz, fS = 48kHz, MCLK = 12.288MHz,

MODE = 1 (FIR audio) -71 -66 dB

DAC LEVEL CONTROL

DAC Attenuation Range AVDACATTN DV1DV2 = 0xF to 0x0 (Note 5) -15 0 dB

DAC Attenuation Step Size 1 dB

DAC Gain Adjust Range AVDACGAIN DV1G = 00 to 11 (Note 5) 0 18 dB

DAC Gain Adjust Step Size 6 dB

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DAC DIGITAL FILTERS

VOICE MODE IIR LOWPASS FILTER (MODE1 = 0)

Passband Cutoff fPLP

Ripple limit cutoff 0.448

x fsHz

-3dB cutoff 0.451

x fs

Passband Ripple f < fPLP -0.1 +0.1 dB

Stopband Cutoff fSLP 0.476

x fsHz

Stopband Attenuation (Note 6) f > fSLP 75 dB

VOICE MODE IIR HIGHPASS FILTER (MODE1 = 0)

Passband Cutoff

(-3dB from Peak) fDHPPB

DVFLT = 0x1 (elliptical tuned for

fs = 16kHz + 217Hz notch)

0.0161

x fs

DVFLT = 0x2 (500Hz Butterworth tuned for

fs = 16kHz)

0.0312

x fs

DVFLT = 0x3 (elliptical tuned for

fs = 8kHz + 217Hz notch)

0.0321

x fs

DVFLT = 0x4 (500Hz Butterworth tuned for

fs = 8kHz)

0.0625

x fs

DVFLT = 0x5 (fs/240 Butterworth) 0.0042

x fs

Stopband Cutoff

(-30dB from Peak) fDHPSB

DVFLT = 0x1 (elliptical tuned for

fs = 16kHz + 217Hz notch)

0.0139

x fs

DVFLT = 0x2 (500Hz Butterworth tuned for

fs = 16kHz)

0.0156

x fs

DVFLT = 0x3 (elliptical tuned for

fs = 8kHz + 217Hz notch)

0.0279

x fs

DVFLT = 0x4 (500Hz Butterworth tuned for

fs = 8kHz)

0.0312

x fs

DVFLT = 0x5 (fs/240 Butterworth) 0.002

x fs

DC Attenuation DCATTEN DVFLT ≠ 000 85 dB

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

STEREO AUDIO MODE FIR LOWPASS FILTER (MODE1 = 1, DHF1/DHF2 = 0, LRCLK < 50kHz)

Passband Cutoff fPLP

Ripple limit cutoff 0.43

x fs

Hz-3dB cutoff 0.47

x fs

-6.02dB cutoff 0.5

x fs

Passband Ripple f < fPLP -0.1 +0.1 dB

Stopband Cutoff fSLP 0.58

x fsHz

Stopband Attenuation (Note 6) f > fSLP 60 dB

STEREO AUDIO MODE FIR LOWPASS FILTER (MODE1 = 1, DHF1/DHF2 = 1 for LRCLK > 50kHz)

Passband Cutoff fPLP

Ripple limit cutoff 0.24

x fsHz

-3dB cutoff 0.31

x fs

Passband Ripple f < fPLP -0.1 +0.1 dB

Stopband Cutoff fSLP 0.477

x fsHz

Stopband Attenuation (Note 6) f < fSLP 60 dB

STEREO AUDIO MODE DC-BLOCKING HIGHPASS FILTER

Passband Cutoff (-3dB from

Peak) fDHPPB DVFLT ≠ 000 (DAI1), DCB2 = 1 (DAI2) 0.000104

x fsHz

DC Attenuation DCATTEN DVFLT ≠ 000 (DAI1), DCB2 = 1 (DAI2) 90 dB

AUTOMATIC LEVEL CONTROL

Dual Band Lowpass Corner

Frequency ALCMB = 1 5 kHz

Dual Band Highpass Corner

Frequency ALCMB = 1 5 kHz

Gain Range 0 12 dB

Low Signal Threshold ALCTH = 111 to 001 -48 -12 dBFS

Release Time ALCRLS = 101 0.25 s

ALCRLS = 000 8

PARAMETRIC EQUALIZER

Number of Bands 5 Bands

Per Band Gain Range -12 +12 dB

Preattenuator Gain Range (Note 5) -15 0 dB

Preattenuator Step Size 1 dB

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DAC-TO-RECEIVER AMPLIFIER PATH

Dynamic Range (Note 4) DR fS = 48kHz, MCLK = 12.288MHz, f = 1kHz 96 dB

Total Harmonic Distortion +

Noise THD+N f = 1kHz, POUT = 25mW, RREC = 32I-70 -63 dB

Click and Pop Level KCP

Peak voltage, A-weighted, 32

samples per second, AVREC

= 0dB

Into shutdown -70

dBV

Out of shutdown -73

PREOUTPUT MIXERS

Level Adjust Gain AVPGAOUT_ (Note 5)

PGAOUTA/PGAOUTB/

PGAOUTC = 0x0 0

PGAOUTA/PGAOUTB/

PGAOUTC = 0xC -25 -23.4 -22

Level Adjust Step Size 2 dB

Mute Attenuation f = 1kHz 85 dB

LINE INPUT-TO-RECEIVER AMPLIFIER PATH

Dynamic Range (Note 4) DR Referenced to full-scale output level 92 dB

Total Harmonic Distortion +

Noise THD+N -70 dB

Power-Supply Rejection Ratio PSRR

VSPKLVDD = 2.8V to 5.5V 54 89

f = 217Hz, VRIPPLE = 100mVP-P -63

f = 1kHz, VRIPPLE = 100mVP-P -63

f = 10kHz, VRIPPLE = 100mVP-P -65

Click-and-Pop Level KCP

Peak voltage, A-weighted, 32

samples per second, AVREC

= 0dB

Into shutdown -57

dBV

Out of shutdown -55

RECEIVER AMPLIFIER

Output Power POUT RREC = 32I, f = 1kHz, THD = 1% 100 mW

Full-Scale Output (Note 7) 1 VRMS

Volume Control AVREC (Note 5) RECVOL = 0x00 -65 -62 -58 dB

RECVOL = 0x1F +7.5 +8 +8.5

Volume Control Step Size

+8dB to +6dB 0.5

+6dB to +0dB 1

0dB to -14dB 2

-14dB to -38dB 3

-38dB to -62dB 4

Mute Attenuation f = 1kHz 95 dB

Output Offset Voltage VOS AVREC = -62dB TA = +25NC±0.13 ±1mV

Capacitive Drive Capability No sustained oscillations RREC = 32I500 pF

RREC = J100

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DAC-TO-SPEAKER AMPLIFIER PATH

Total Harmonic Distortion +

Noise THD+N f = 1kHz, POUT = 250mW, ZSPK = 8I + 68FH-71 dB

Crosstalk SPKL to SPKR and SPKR to SPKL,

POUT = 640mW, f = 1kHz -75 dB

Output Noise A-weighted 43 FVRMS

Click-and-Pop Level KCP

Peak voltage, A-weighted,

32 samples per second,

AVSPK_ = 0dB

Into shutdown -65

dBV

Out of shutdown -65

LINE INPUT-TO-SPEAKER AMPLIFIER PATH

Total Harmonic Distortion +

Noise THD+N f = 1kHz, POUT = 200mW, ZSPK = 8I + 68FH-66 dB

Output Noise A-weighted 56 FVRMS

Power-Supply Rejection Ratio PSRR

VSPKLVDD = VRIPPLE = 2.8V to 5.5V 43 60

f = 217Hz, VRIPPLE = 100mV 75

f = 1kHz, VRIPPLE = 100mV 73

f = 10kHz, VRIPPLE = 100mV 50

Click-and-Pop Level KCP

Peak voltage, A-weighted,

32 samples per second,

AVSPK_ = 0dB

Into shutdown -48

dBV

Out of shutdown -50

SPEAKER AMPLIFIER

Output Power POUT f = 1kHz, THD = 1%,

ZSPK = 8I + 68FH

VSPKLVDD =

VSPKRVDD = 5.0V 1370

VSPKLVDD =

VSPKRVDD = 4.2V 954

VSPKLVDD =

VSPKRVDD = 3.7V 733

VSPKLVDD =

VSPKRVDD = 3.2V 544

Full-Scale Output (Note 7) 2 VRMS

Volume Control (Note 5) AVSPK_ SPVOLL/SPVOLR = 0x00 -69 -64 -59 dB

SPVOLL/SPVOLR = 0x1F +7.5 +8 +8.5

Volume Control Step Size

+8dB to +6dB 0.5

+6dB to +0dB 1

0dB to -14dB 2

-14dB to -38dB 3

-38dB to -64dB 4

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Mute Attenuation f = 1kHz 86 dB

Output Offset Voltage VOS AVSPK_ = -64dB, TA = +25NC±0.25 ±1.25 mV

EXCURSION LIMITER

Upper-Corner Frequency Range DHPUCF = 001 to 100 400 1000 Hz

Lower-Corner Frequency DHPLCF = 01 to 10 400 Hz

Biquad Minimum Corner

Frequency

DHPUCF = 000 (fixed mode) 100

DHPUCF = 001 200

DHPUCF = 010 300

DHPUCF = 011 400

DHPUCF = 100 500

Threshold Voltage

ZSPK = 8I + 68FH,

VSPKLVDD = VSPKRVDD =

5.5V, AVSPK_ = +8dB

DHPTH = 000 0.34

DHPTH = 111 4.95

Release Time ALCRLS = 101 0.25 s

ALCRLS = 000 4

POWER LIMITER

Attenuation -64 dB

Threshold

ZSPK = 8I + 68FH,

VSPKLVDD = VSPKRVDD =

5.5V, AVSPK_ = +8dB

PWRTH = 0x1 0.05

PWRTH = 0xF 1.80

Time Constant 1 tPWR1 PWRT1 = 0x1 0.5 s

PWRT1 = 0xF 8.7

Time Constant 2 tPWR2 PWRT2 = 0x1 to 0xF 0.5 min

PWRT2 = 0xF 8.7

Weighting Factor kPWR PWRK = 000 to 111 12.5 100 %

DISTORTION LIMITER

Distortion Limit THDCLP = 0x1 < 1 %

THDCLP = 0xF 24

Release Time Constant THDT1 = 000 0.76 s

THDT1 = 111 6.2

DAC-TO-HEADPHONE AMPLIFIER PATH

Dynamic Range (Note 4) DR fS = 48kHz, MCLK =

12.288MHz

Master or slave mode 100 dB

Slave mode 94

Total Harmonic Distortion +

Noise THD+N

fS = 48kHz, MCLK = 12.288MHz,

f = 1kHz, POUT = 20mW

RHP = 16I-71 -64

RHP = 32I-75

fS = 48kHz, MCLK = 12.288MHz,

f = 1kHz, VOUT = 1VRMS, RHP = 10kI-79

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Crosstalk

f = 1kHz, Input = -1dBFS, RHP = 10kI-82 dB

HPL to HPR and HPR to HPL,

POUT = 5mW, f = 1kHz, RHP = 32I-82 dB

Power-Supply Rejection Ratio PSRR

VAVDD = VHPVDD = 1.65V to 2.0V 60 84

f = 217Hz, VRIPPLE = 100mV, AVVOL = 0dB 92

f = 1kHz, VRIPPLE = 100mV, AVVOL = 0dB 91

f = 10kHz, VRIPPLE = 100mV, AVVOL = 0dB 57

DAC Path Phase Delay

1kHz, 0dB input,

highpass filter

disabled measured

from digital input to

analog output

MODE = 0 (voice) 8kHz 2.2

MODE = 0 (voice)

16kHz 1.1

MODE = 1 (music)

8kHz 4.5

MODE = 1 (music)

48kHz 0.76

Gain Error 1 %

Channel Gain Mismatch 0.5 %

Click-and-Pop Level KCP

Peak voltage, A-weighted,

32 samples per second,

AVHP_ = 0dB

Into shutdown -66

dBV

Out of

shutdown -67

LINE INPUT-TO-HEADPHONE AMPLIFIER PATH

Total Harmonic Distortion +

Noise THD+N VIN = 1VP-P, f =1kHz, RHP = 32I-70 dB

Dynamic Range (Note 4) DR 91 dB

Power-Supply Rejection Ratio PSRR

VAVDD = VHPVDD = 1.65V to 2.0V 42 66

f = 217Hz, VRIPPLE = 100mVP-P 62

f = 1kHz, VRIPPLE = 100mVP-P 57

f = 10kHz, VRIPPLE = 100mVP-P 41

Click and Pop Level KCP

Peak voltage, A-weighted,

32 samples per second,

AVHP_ = 0dB

Into shutdown -62

dBV

Out of

shutdown -60

HEADPHONE AMPLIFIER

Output Power POUT f = 1kHz, THD = 1% RHP = 32I32 mW

RHP = 16I40

Full-Scale Output (Note 7) 1 VRMS

Volume Control AVHP_ TA = +25NC (Note 5) HPVOL_ = 0x00 -71 -67 -66 dB

HPVOL_ = 0x1F 2.4 3 3.5

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Volume Control Step Size

+3dB to +1dB 0.5

+1dB to -5dB 1

-5dB to -19dB 2

-19dB to -43dB 3

-43dB to -67dB 4

Mute Attenuation f = 1kHz 82 dB

Output Offset Voltage VOS AVHP_ = -67dB TA = +25NC±0.2 ±1mV

TA = TMIN to TMAX ±2

Capacitive Drive Capability No sustained

oscillations

RHP = 32I500 pF

RHP = J100

Charge Pump Oscillator

Frequency fCP 300 667 900 kHz

Slow mode 74

SPEAKER BYPASS SWITCH

On-Resistance RON ISPKL_ = 100mA, SPKBYP = 1,

VRXIN_ = [0V, VSPKLVDD] 2.8 4.5 I

Total Harmonic Distortion +

Noise THD+N

VIN = 2VP-P, VCM = VSPKLVDD/2,

ZSPK = 8I + 68FH, f = 1kHz,

SPKBYP = 1

RS = 10I-77

RS = 0I-60

Off-Isolation VIN = 2VP-P, VCM = VSPKLVDD/2,

ZL = 8I + 68FH, f = 1kHz 96 dB

Off-Leakage Current VRXIN_ = [0V, VSPKLVDD],

VSPKL_ = [VSPKLVDD, 0V] -1 +1 FA

RECEIVER BYPASS SWITCH

On-Resistance RON IRECP = 100mA, RECBYP = 1,

VRECN = [0V, VSPKLVDD]1.2 2 I

Total Harmonic Distortion +

Noise THD+N VIN = 2VP-P, VCM = VSPKLVDD/2,

RL = 32I, f = 1kHz, RECBYP = 1 -66 %

Off-Isolation VIN = 2VP-P, VCM = VSPKLVDD/2,

RL = 32I, f = 1kHz 80 dB

Off-Leakage Current VRECP = [0V, VSPKLVDD],

VRECN = [VSPKLVDD, 0V] -15 +15 FA

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS = 1.

TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 1)

DIGITAL INPUT/OUTPUT CHARACTERISTICS

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = 1.65V to 2.0V, VSPKLVDD = VSPKRVDD = 3.7V, TA = TMIN to TMAX, unless

otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

JACK DETECTION

JACKSNS High Threshold VTH1

MICBIAS enabled 0.92 x

VMICBIAS

0.95 x

VMICBIAS

0.98 x

VMICBIAS V

MICBIAS disabled 0.92 x

VSPKLVD

0.95 x

VSPKLVDD

0.98 x

VSPKLVD

JACKSNS Low Threshold VTH2

MICBIAS enabled 0.06 x

VMICBIAS

0.10 x

VMICBIAS

0.17 x

VMICBIAS V

MICBIAS disabled 0.06 x

VSPKLVD

0.10 x

VSPKLVDD

0.17 x

VSPKLVD

JACKSNS Sense Voltage VSENSE MICBIAS disabled VSPKLVDD V

JACKSNS Sense Resistance RSENSE MICBIAS disabled, JDWK = 0 1.7 2.4 2.9 kI

JACKSNS Weak Pullup Current IWPU MICBIAS disabled, JDWK = 1 2 5 9.5 FA

JACKSNS Deglitch Period tGLITCH JDEB = 00 25 ms

JDEB = 11 200

BATTERY ADC

Input Voltage Range 2.8 5.5 V

LSB Size 0.1 V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

MCLK

Input High Voltage VIH 1.2 V

Input Low Voltage VIL 0.6 V

Input Leakage Current IIH, IIL VDVDD = 2.0V, VIN = 0V, 5.5V, TA = +25°C -1 +1 FA

Input Capacitance 10 pF

SDINS1, BCLKS1, LRCLKS1—INPUT

Input High Voltage VIH 0.7 x

DVDDS1 V

Input Low Voltage VIL 0.29 x

DVDDS1 V

Input Hysteresis 200 mV

Input Leakage Current IIH, IIL VDVDDS1 = 3.6V, VIN = 0V, 3.6V; TA = +25°C -1 +1 FA

Input Capacitance 10 pF

Stereo Audio CODEC

with FlexSound Technology

MAX9888

DIGITAL INPUT/OUTPUT CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = 1.65V to 2.0V, VSPKLVDD = VSPKRVDD = 3.7V, TA = TMIN to TMAX, unless

otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

BCLKS1, LRCLKS1, SDOUTS1—OUTPUT

Output Low Voltage VOL VDVDDS1 = 1.65V, IOL = 3mA 0.4 V

Output High Voltage VOH VDVDDS1 = 1.65V, IOH = 3mA DVDDS1

- 0.4 V

Input Leakage Current IIH, IIL VDVDD = 2.0V, VIN = 0V, 5.5V; TA = +25°C,

high-impedance state -1 +1 FA

SDINS2, BCLKS2, LRCLKS2—INPUT

Input High Voltage VIH 0.7 x

DVDDS2 V

Input Low Voltage VIL 0.29 x

DVDDS2 V

Input Hysteresis 200 mV

Input Leakage Current IIH, IIL VDVDDS2 = 3.6V, VIN = 0V, 3.6V; TA = +25°C -1 +1 FA

Input Capacitance 10 pF

BCLKS2, LRCLKS2, SDOUTS2—OUTPUT

Output Low Voltage VOL VDVDDS2 = 1.65V, IOL = 3mA 0.4 V

Output High Voltage VOH VDVDDS2 = 1.65V, IOH = 3mA DVDDS2

- 0.4 V

Input Leakage Current IIH, IIL VDVDD = 2.0V, VIN = 0V, 5.5V; TA = +25NC,

high-impedance state -1 +1 FA

SDA, SCL—INPUT

Input High Voltage VIH 0.7 x

DVDD V

Input Low Voltage VIL 0.3 x

DVDD V

Input Hysteresis 210 mV

Input Leakage Current IIH, IIL VDVDD = 2.0V, VIN = 0V, 5.5V, TA = +25NC -1 +1 FA

Input Capacitance 10 pF

SDA, IRQ—OUTPUT

Output High Current IOH VOUT = 5.5V, TA = +25°C 1 mA

Output Low Voltage VOL VDVDD = 1.65V, IOL = 3mA 0.2 x

DVDD V

DIGMICDATA—INPUT

Input High Voltage VIH 0.65 x

DVDD V

Input Low Voltage VIL 0.35 x

DVDD V

Input Hysteresis 125 mV

Input Leakage Current IIH, IIL VDVDD = 2.0V, VIN = 0V, 2.0V; TA = +25°C -25 +25 FA

Input Capacitance 10 pF

Stereo Audio CODEC

with FlexSound Technology

MAX9888

INPUT CLOCK CHARACTERISTICS

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V, TA = TMIN to TMAX, unless otherwise

noted. Typical values are at TA = +25NC.) (Note 1)

DIGITAL INPUT/OUTPUT CHARACTERISTICS (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = 1.65V to 2.0V, VSPKLVDD = VSPKRVDD = 3.7V, TA = TMIN to TMAX, unless

otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

MCLK Input Frequency fMCLK 10 60 MHz

MCLK Input Duty Cycle PSCLK = 01 40 50 60 %

PSCLK = 10 or 11 30 70

Maximum MCLK Input Jitter 100 psRMS

LRCLK Sample Rate (Note 8) DHF_ = 0 8 48 kHz

DHF_ = 1 48 96

DAI1 LRCLK Average Frequency

Error (Note 9)

FREQ1 = 0x8 to 0xF 0 0 %

FREQ1 = 0x0 -0.025 +0.025

DAI2 LRCLK Average Frequency

Error (Note 9) -0.025 +0.025 %

PLL Lock Time Rapid lock mode 2 7 ms

Nonrapid lock mode 12 25

Maximum LRCLK Jitter to Maintain

PLL Lock 100 ns

Soft-Start/Stop Time 10 ms

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DIGMICCLK—OUTPUT

Output Low Voltage VOL VDVDD = 1.65V, IOL = 1mA 0.4 V

Output High Voltage VOH VDVDD = 1.65V, IOH = 1mA DVDD -

0.4 V

Stereo Audio CODEC

with FlexSound Technology

MAX9888

AUDIO INTERFACE TIMING CHARACTERISTICS

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = 1.65V, VSPKLVDD = VSPKRVDD = 2.8V, TA = TMIN to TMAX, unless otherwise

noted. Typical values are at TA = +25NC.) (Note 1)

Figure 1. Non-TDM Audio Interface Timing Diagrams (TDM_ = 0)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

BCLK Cycle Time tBCLK Slave mode 90 ns

BCLK High Time tBCLKH Slave mode 20 ns

BCLK Low Time tBCLKL Slave mode 20 ns

BCLK or LRCLK Rise and Fall Time tR, tFMaster mode, CL = 15pF ns

SDIN to BCLK Setup Time tSETUP 20 ns

LRCLK to BCLK Setup Time tSYNCSET Slave mode 20 ns

SDIN to BCLK Hold Time tHOLD 20 ns

LRCLK to BCLK Hold Time tSYNCHOLD Slave mode 20 ns

Minimum Delay Time from LSB

BCLK Falling Edge to

High-Impedance State

tHIZOUT Master mode, TDM_ = 1 42 ns

LRCLK Rising Edge to SDOUT

MSB Delay tSYNCTX CL = 30pF, TDM_ = 1, FSW_ = 1 50 ns

BCLK to SDOUT Delay tCLKTX CL = 30pF TDM_ = 1, BCLK rising edge 50 ns

TDM_ = 0 50

Delay Time from BCLK to LRCLK tCLKSYNC Master

mode

TDM_ = 1 -15 +15

TDM_ = 0 0.8 x

tBCLKL

Delay Time from LRCLK to BCLK

After LSB tENDSYNC Master

mode TDM_ = 1, FSW_ = 1 20 ns

tCLKTX

tSETUP tHOLD

tBCLK

tBCLKH tBCLKL

MSBLSB

LSB

BCLK

(OUTPUT)

LRCLK

(OUTPUT)

SDOUT

(OUTPUT)

SDIN

(INPUT)

BCLK

(INPUT)

LRCLK

(INPUT)

SDOUT

(OUTPUT)

SDIN

(INPUT)

MASTER MODE

tSETUP tHOLD

MSB

LSB

LSB HI-Z

SLAVE MODE

HI-Z MSB

tCLKSYNC

tHIZOUT tCLKTX

tSYNCSET

tHIZOUT

Stereo Audio CODEC

with FlexSound Technology

MAX9888

DIGITAL MICROPHONE TIMING CHARACTERSTICS

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = 2.0V, VSPKLVDD = VSPKRVDD = 2.8V, TA = TMIN to TMAX, unless otherwise

noted. Typical values are at TA = +25NC.) (Note 1)

Figure 2. TDM Audio Interface Timing Diagram (TDM_ = 1, FSW_ = 0)

Figure 3. TDM Audio Interface Timing Diagram (TDM_ = 1, FSW_ = 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DIGMICCLK Frequency fMICCLK MICCLK = 00 MCLK/8 MHz

MICCLK = 01 MCLK/6

DIGMICDATA to DIGMICCLK

Setup Time tSU,MIC Either clock edge 20 ns

DIGMICDATA to DIGMICCLK

Hold Time tHD,MIC Either clock edge 0 ns

LRCLK (OUTPUT)

BCLK (OUTPUT)

SDOUT (OUTPUT)

SDIN (INPUT)

tCLKTX

tHIZOUT

HI-ZLSB

tHOLD

tSETUP

LSB

MSB

tCLKSYNC

LRCLK (INPUT)

BCLK (INPUT)

SDOUT (OUTPUT)

SDIN (INPUT)

tCLKTX

tHIZOUT

HI-ZLSB

tHOLD

tSETUP

LSB

tSYNCHOLD

MSB

tBCLKH tBCLKL

tBCLK

tSYNCSET

MASTER MODE SLAVE MODE

tCLKSYNC

tBCLKH tBCLKL

tCLKSYNC

LRCLK (OUTPUT)

BCLK (OUTPUT)

SDOUT (OUTPUT)

SDIN (INPUT)

MASTER MODE

HI-ZLSB MSB

tSYNCTX

tENDSYNC

LSB MSB

SLAVE MODE

HI-ZLSB

LSB

MSB

tCLKTX

tHIZOUT

tHOLD

tSETUP tHOLD

tSETUP

LRCLK (INPUT)

BCLK (INPUT)

SDOUT (OUTPUT)

SDIN (INPUT)

tBCLK

tSYNCTX tCLKTX

tHIZOUT

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Figure 4. Digital Microphone Timing Diagram

I2C TIMING CHARACTERSTICS

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = 1.65V to 2.0V, VSPKLVDD = VSPKRVDD = 3.7V, TA = TMIN to TMAX, unless

otherwise noted. Typical values are at TA = +25NC.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Serial-Clock Frequency fSCL Guaranteed by SCL pulse-width low and

high 0 400 kHz

Bus Free Time Between STOP and

START Conditions tBUF 1.3 Fs

Hold Time (Repeated) START

Condition tHD,STA 0.6 Fs

SCL Pulse-Width Low tLOW 1.3 Fs

SCL Pulse-Width High tHIGH 0.6 Fs

Setup Time for a Repeated START

Condition tSU,STA 0.6 Fs

Data Hold Time tHD,DAT RPU = 475I, CB = 100pF, 400pF 0 900 ns

Data Setup Time tSU,DAT 100 ns

SDA and SCL Receiving Rise Time tR(Note 10) 20 +

0.1CB300 ns

SDA and SCL Receiving Fall Time tF(Note 10) 20 +

0.1CB300 ns

SDA Transmitting Fall Time tFRPU = 475I, CB = 100pF, 400pF (Note 10) 20 +

0.05CB250 ns

Setup Time for STOP Condition tSU,STO 0.6 Fs

Bus Capacitance CBGuaranteed by SDA transmitting fall time 400 pF

Pulse Width of Suppressed Spike tSP 0 50 ns

1/fMICCLK

tHD,MIC tSU,MIC

LEFT RIGHT LEFT RIGHT

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Note 1: The IC is 100% production tested at TA = +25NC. Specifications over temperature limits are guaranteed by design.

Note 2: Analog supply current = IAVDD + IHPVDD. Speaker supply current = ISPKLVDD + ISPKRVDD. Digital supply current = IDVDD

+ IDVDDS1 + IDVDDS2.

Note 3: Clocking all zeros into the DAC. Slave mode.

Note 4: Dynamic range measured using the EIAJ method. -60dBFS, 1kHz output signal, A-weighted and normalized to 0dBFS.

f = 20Hz to 20kHz.

Note 5: Gain measured relative to the 0dB setting.

Note 6: The filter specification is accurate only for synchronous clocking modes, where NI is a multiple of 0x1000.

Note 7: 0dBFS for DAC input. 1VP-P for INA/INB inputs.

Note 8: LRCLK may be any rate in the indicated range. Asynchronous or noninteger MCLK/LRCLK ratios may exhibit some full-

scale performance degradation compared to synchronous integer related MCLK/LRCLK ratios.

Note 9: In master-mode operation, the accuracy of the MCLK input proportionally determines the accuracy of the sample clock rate.

Note 10: CB is in pF.

Figure 5. I2C Interface Timing Diagram

Power Consumption

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V)

MODE IAVDD

(mA)

IHPVDD

(mA)

ISPKLVDD +

ISPKRVDD

(mA)

IDVDD

(mA)

IDVDDS1 + IDVDDS2

(mA)

POWER

(mW)

DAC Playback 48kHz Stereo HP

DAC à HP

24-bit, music filters

1.35 1.37 1.65 2.91 0.02 16.25

DAC Playback 48kHz Stereo HP

DAC à HP

24-bit, music filters, 0.1mW/channel,

RHP = 32I

1.35 4.19 1.65 3.02 0.02 21.55

DAC Playback 48kHz Stereo HP

DAC à HP

24-bit, music filters, ALC enabled

1.35 1.37 1.65 2.96 0.02 16.36

SCL

SDA

tRtF

tBUF

START

CONDITION

STOP

CONDITION

REPEATED START CONDITION

START CONDITION

tSU,STO

tHD,STA

tSU,STA

tHD,DAT

tSU,DAT

tLOW

tHIGH

tHD,STA

tSP

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Power Consumption (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V)

MODE IAVDD

(mA)

IHPVDD

(mA)

ISPKLVDD +

ISPKRVDD

(mA)

IDVDD

(mA)

IDVDDS1 + IDVDDS2

(mA)

POWER

(mW)

DAC Playback 48kHz Stereo HP

DAC à HP

24-bit, music filters, EQ enabled

1.35 1.36 1.65 3.27 0.02 16.90

DAC Playback 48kHz Stereo HP

DAC à HP

24-bit, music filters, digital mixing

1.34 1.36 1.65 2.91 0.02 16.27

DAC Playback 44.1kHz Stereo HP

DAC à HP

24-bit, music filters

1.35 1.37 1.69 2.85 0.02 16.29

DAC Playback 8kHz Stereo HP

DAC à HP

16-bit, voice filters

1.35 1.37 1.65 1.46 0.01 13.65

DAC Playback 8kHz Mono HP

DAC à HP

16-bit, voice filters

1.00 0.71 1.01 1.36 0.01 9.27

DAC Playback 48kHz Stereo SPK

DAC à SPK

24-bit, music filters

1.83 0.02 8.22 2.92 0.02 39.09

DAC Playback 48kHz Mono SPK

DAC à SPK

24-bit, music filters

1.25 0.02 4.31 2.82 0.02 23.32

Line Stereo Record 48kHz

INA à ADC

16-bit, music filters

9.91 0.02 0.39 1.62 0.11 22.48

Line Stereo Record 48kHz, Stereo HP

INA à ADC

INA à HP

16-bit, music filters

10.64 2.65 0.66 1.63 0.11 29.51

Line Stereo Record 48kHz, Stereo SPK

INA à ADC

INA à SPK

16-bit, music filters

10.97 0.03 7.15 1.63 0.12 49.50

Differential Line Record 48kHz

INA à ADCL

INB à ADCR

Differential input

10.49 0.02 0.39 1.63 0.16 23.58

Microphone Stereo Record 48kHz

MIC1/2 à ADC

16-bit, music filters

10.88 0.03 0.69 1.62 0.17 25.43

Microphone Stereo Record 8kHz

MIC1/2 à ADC

16-bit, voice filters

10.77 0.02 0.64 1.03 0.06 23.78

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Power Consumption (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V)

MODE IAVDD

(mA)

IHPVDD

(mA)

ISPKLVDD +

ISPKRVDD

(mA)

IDVDD

(mA)

IDVDDS1 + IDVDDS2

(mA)

POWER

(mW)

Microphone Mono Record 48kHz

MIC1/2 à ADC

16-bit, music filters

6.01 0.02 0.66 1.37 0.10 15.97

Microphone Mono Record 8kHz

MIC1/2 à ADC

16-bit, voice filters

5.95 0.02 0.64 0.98 0.04 14.94

Microphone Mono Record 8kHz

MIC1/2 à ADC

16-bit, voice filters, AGC

5.95 0.02 0.64 0.98 0.04 15.00

Microphone Mono Record 8kHz

MIC1/2 à ADC

16-bit, voice filters, AGC, noise gate

5.96 0.02 0.64 0.98 0.04 14.98

Full-Duplex 48kHz Stereo HP

MIC1/2 à ADC

DAC à HP

24-bit, music filters

11.38 1.37 1.70 3.56 0.19 36.06

Full-Duplex 8kHz Mono RCV

MIC1 à ADC

DAC à REC

16-bit, voice filters

6.35 0.02 1.98 1.47 0.03 21.47

Full-Duplex 8kHz Mono HP

MIC1 à ADC

DAC à HP

16-bit, voice filters

6.09 0.71 1.01 1.46 0.03 18.72

Full-Duplex 8kHz Stereo HP

MIC1/2 à ADC

DAC à HP

16-bit, voice filters

10.92 1.37 1.09 1.51 0.05 28.95

Line Playback Stereo HP

INA à HP

Single-ended inputs

1.89 2.65 0.58 0.03 0.01 10.41

Line Playback Stereo SPK

INA à SPK

Single-ended inputs

2.21 0.02 7.05 0.04 0.02 30.19

Line Playback Mono SPK

INA à SPK

Single-ended inputs

1.68 0.02 3.70 0.03 0.02 16.90

Differential Line Playback Stereo HP

INA à HPL

INB à HPR

Differential input

2.46 2.65 0.58 0.03 0.01 11.42

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

Microphone to ADC

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (MIC TO ADC)

MAX9888 toc01

FREQUENCY (Hz)

THD+N RATIO (dB)

1000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 10,000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

VIN = 1VP-P

AVMICPRE_ = 0dB

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (MIC TO ADC)

MAX9888 toc02

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-80

-70

-60

-50

-40

-30

-20

-10

-90

10 100,000

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

VIN = 1VP-P

AVMICPRE_ = 0dB

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (MIC TO ADC)

MAX9888 toc03

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 100,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

VIN = 1VP-P

AVMICPRE_ = 0dB

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (MIC TO ADC)

MAX9888 toc04

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 100,000

MCLK = 12.288MHz

LRCLK = 96kHz

NI MODE

VIN = 1VP-P

AVMICPRE_ = 0dB

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (MIC TO ADC)

MAX9888 toc05

FREQUENCY (Hz)

THD+N RATIO (dB)

1000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 10,000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

VIN = 0.1VP-P

AVMICPRE_ = +20dB

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (MIC TO ADC)

MAX9888 toc06

FREQUENCY (Hz)

THD+N RATIO (dB)

1000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 10,000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

VIN = 0.032VP-P

AVMICPRE_ = +30dB

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

GAIN vs. FREQUENCY (MIC TO ADC)

MAX9888 toc07

FREQUENCY (Hz)

NORMALIZED GAIN (dB)

1000100

-75

-65

-55

-45

-35

-25

-15

-5

-85

10 10,000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

VIN = 1VP-P

AVMICPRE_ = 0dB

MODE = 0

MODE = 1

COMMON-MODE REJECTION

RATIO vs. FREQUENCY (MIC TO ADC)

MAX9888 toc08

FREQUENCY (Hz)

CMRR (dB)

10,0001000100

10 100,000

AVMICPRE_ = +30dB

AVMICPRE_ = +20dB

AVMICPRE_ = 0dB

VOUT, DIFF = 0dBFS

POWER-SUPPLY REJECTION

RATIO vs. FREQUENCY (MIC TO ADC)

MAX9888 toc09

FREQUENCY (Hz)

PSRR (dB)

10,0001000100

-100

-80

-60

-40

-20

-120

10 100,000

VRIPPLE = 200mVP-P

INPUTS AC GROUNDED

RIPPLE ON

SPKLVDD, SPKRVDD

RIPPLE ON AVDD,

DVDD, HPVDD

FFT, 0dBFS (MIC TO ADC)

MAX9888 toc10

FREQUENCY (Hz)

AMPLITUDE (dBV)

350030002500200015001000500

-120

-100

-80

-60

-40

-20

-140

0 4000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

AVMICPRE_ = 0dB

FFT, -60dBFS (MIC TO ADC)

MAX9888 toc11

FREQUENCY (Hz)

AMPLITUDE (dBV)

350030002500200015001000500

-120

-100

-80

-60

-40

-20

-140

0 4000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

AVMICPRE_ = 0dB

FFT, 0dBFS (MIC TO ADC)

MAX9888 toc12

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

AVMICPRE_ = 0dB

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

FFT, -60dBFS (MIC TO ADC)

MAX9888 toc13

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

AVMICPRE_ = 0dB

FFT, 0dBFS (MIC TO ADC)

MAX9888 toc14

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

AVMICPRE_ = 0dB

FFT, -60dBFS (MIC TO ADC)

MAX9888 toc15

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

AVMICPRE_ = 0dB

FFT, 0dBFS (MIC TO ADC)

MAX9888 toc16

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 12.288MHz

LRCLK = 96kHz

NI MODE

AVMICPRE_ = 0dB

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

FFT, -60dBFS (MIC TO ADC)

MAX9888 toc17

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 12.288MHz

LRCLK = 96kHz

NI MODE

AVMICPRE_ = 0dB

SOFTWARE TURN-ON/OFF RESPONSE

(MIC TO ADC)

MAX9888 toc19

SCL

2V/div

ADC

OUTPUT

0.5V/div

10ms/div

ADC ENABLE/DISABLE RESPONSE

(MIC TO ADC)

MAX9888 toc18

SCL

2V/div

ADC

OUTPUT

0.5V/div

10ms/div

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

Line to ADC

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (LINE TO ADC)

MAX9888 toc20

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-80

-70

-60

-50

-40

-30

-20

-10

-90

10 100,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

VIN = 1.4VP-P

AVPGAIN_ = -6dB

CIN = 1µF

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (LINE TO ADC)

MAX9888 toc21

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 100,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

VIN = 1VP-P

CIN = 1µF

AVPGAIN_ = 0dB

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (LINE TO ADC)

MAX9888 toc22

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 100,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

VIN = 0.1VP-P

AVPGAIN_ = +20dB

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY (LINE TO ADC)

MAX9888 toc23

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 100,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

VIN = 1VRMS

EXTERNAL GAIN MODE

RIN = 56kI, CIN = 1µF

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (LINE TO ADC)

MAX9888 toc24

FREQUENCY (Hz)

PSRR (dB)

10,0001000100

-100

-80

-60

-40

-20

-120

10 100,000

VRIPPLE = 200mVP-P

INPUTS AC GROUNDED

RIPPLE ON AVDD,

DVDD, HPVDD

RIPPLE ON

SPKLVDD, SPKRVDD

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

Digital Loopback

FFT, 0dBFS

(SDINS1 TO SDOUTS2 DIGITAL LOOPBACK)

MAX9888 toc25

FREQUENCY (Hz)

AMPLITUDE (dBFS)

15,00010,0005000

-160

-140

-120

-100

-80

-60

-40

-20

-180

0 20,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

FFT, -60dBFS

(SDINS1 TO SDOUTS2 DIGITAL LOOPBACK)

MAX9888 toc26

FREQUENCY (Hz)

AMPLITUDE (dBFS)

15,00010,0005000

-160

-140

-120

-100

-80

-60

-40

-20

-180

0 20,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

Analog Loopback

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

(LINE TO ADC TO DAC TO HEADPHONE)

MAX9888 toc27

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-80

-70

-60

-50

-40

-30

-20

-10

-90

10 100,000

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

RHP = 32I, CIN = 1µF

POUT = 0.025W

POUT = 0.01W

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

(LINE TO ADC TO DAC TO HEADPHONE )

MAX9888 toc28

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-80

-70

-60

-50

-40

-30

-20

-10

-90

10 100,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 32I, CIN = 1µF

POUT = 0.025W

POUT = 0.01W

FFT, 0dBFS

(LINE TO ADC TO DAC TO HEADPHONE)

MAX9888 toc29

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

RHP = 32I

FFT, -60dBFS

(LINE TO ADC TO DAC TO HEADPHONE)

MAX9888 toc30

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

RHP = 32I

FFT, 0dBFS

(LINE TO ADC TO DAC TO HEADPHONE)

MAX9888 toc31

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 32I

FFT, -60dBFS

(LINE TO ADC TO DAC TO HEADPHONE)

MAX9888 toc32

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 32I

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

DAC to Receiver

TOTAL HARMONIC DISTORTION

vs. OUTPUT POWER (DAC TO RECEIVER)

MAX9888 toc33

OUTPUT POWER (W)

THD+N RATIO (dB)

0.100.080.060.040.02

-80

-70

-60

f = 100Hz

-50

-40

-30

-20

-10

-90

0 0.12

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

RREC = 32I

AVREC = +8dB

f = 3000Hz

f = 1000Hz

TOTAL HARMONIC DISTORTION

vs. FREQUENCY (DAC TO RECEIVER)

MAX9888 toc34

FREQUENCY (Hz)

THD+N RATIO (dB)

1000100

-80

-70

-60

-50

-40

-30

-20

-10

-90

10 10,000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

RREC = 32I

POUT = 0.05W

POUT = 0.025W

OUTPUT POWER vs. SUPPLY VOLTAGE

(DAC TO RECEIVER)

MAX9888 toc35

SUPPLY VOLTAGE (V)

OUTPUT POWER PER CHANNEL (mW)

5.04.53.0 3.5 4.0

100

110

120

130

140

2.5 5.5

THD+N = 10%

THD+N = 1%

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

RREC = 32I

AVREC = +8dB

GAIN vs. FREQUENCY

(DAC TO RECEIVER)

MAX9888 toc36

FREQUENCY (Hz)

NORMALIZED GAIN (dB)

1000100

-4

-3

-2

-1

-5

10 10,000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

RREC = 32I

POWER CONSUMPTION vs. OUTPUT

POWER (DAC TO RECEIVER)

MAX9888 toc37

OUTPUT POWER (W)

POWER CONSUMPTION (W)

0.100.080.060.040.02

0.05

0.10

0.15

0.20

0.25

0 0.12

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

RREC = 32I

AVREC = +8dB

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (DAC TO RECEIVER)

MAX9888 toc38

FREQUENCY (Hz)

PSRR (dB)

10,0001000100

-80

-60

-40

-20

-100

10 100,000

VRIPPLE = 200mVP-P

ALL ZEROS AT INPUT

RIPPLE ON SPKLVDD,

SPKRVDD

RIPPLE ON AVDD,

DVDD, HPVDD

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

MAX9888 toc39

RECEIVER

OUTPUT

1V/div

SCL

2V/div

10ms/div

SOFTWARE TURN-ON/OFF RESPONSE

(DAC TO RECEIVER, VSEN = 0)

MAX9888 toc40

RECEIVER

OUTPUT

1V/div

SCL

2V/div

10ms/div

SOFTWARE TURN-ON/OFF RESPONSE

(DAC TO RECEIVER, VSEN = 1) FFT, 0dBFS (DAC TO RECEIVER)

MAX9888 toc41

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

RREC = 32I

FFT, -60dBFS (DAC TO RECEIVER)

MAX9888 toc42

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

RREC = 32I

FREQUENCY (kHz)

AMPLITUDE (dBm)

1000100101

-100

-80

-60

-40

-20

-120

0 10,000

WIDEBAND FFT, 0dBFS

(DAC TO RECEIVER)

MAX9888 toc43

MCLK = 13MHz

LRCLK = 8kHz

PLL MODE

RREC = 32I

FREQUENCY (kHz)

AMPLITUDE (dBm)

1000100101

-100

-80

-60

-40

-20

-120

0 10,000

WIDEBAND FFT, -60dBFS

(DAC TO RECEIVER)

MAX9888 toc44

MCLK = 13MHz

LRCLK = 8kHz

PLL MODE

RREC = 32I

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

Line to Receiver

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

(LINE TO RECEIVER)

MAX9888 toc45

OUTPUT POWER (W)

THD+N RATIO (dB)

0.080.060.02 0.04

-70

-60

-50

-40

-20

-30

-10

-80

0 0.10

RREC = 32I

AVREC = +8dB

f = 6000Hz

f = 1000Hz

f = 100Hz

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

(LINE TO RECEIVER)

MAX9888 toc46

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-80

-70

-60

-50

-40

-30

-20

-10

-90

10 100,000

RREC = 32I

CIN = 1µF

AVREC = +8dB

POUT = 0.025W

POUT = 0.05W

GAIN vs. FREQUENCY (LINE TO RECEIVER)

MAX9888 toc47

FREQUENCY (Hz)

NORMALIZED GAIN (dB)

10,0001000100

-4

-3

-2

-1

-5

10 100,000

RREC = 32I

CIN = 1µF

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (LINE TO RECEIVER)

MAX9888 toc48

FREQUENCY (Hz)

PSRR (dB)

10,0001000100

-80

-60

-40

-20

-100

10 100,000

VRIPPLE = 200mVP-P

INPUT AC GROUNDED

RIPPLE ON SPKLVDD,

SPKRVDD

RIPPLE ON AVDD,

DVDD, HPVDD

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

DAC to Speaker

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO SPEAKER)

MAX9888 toc49

OUTPUT POWER (W)

THD+N RATIO (dB)

1.00.80.60.40.2

-80

-70

-60

-50

-40

-30

-20

-10

-90

0 1.2

VSPK_VDD = 4.2V

MCLK = 12.288MHz, LRCLK = 48kHz

NI MODE

ZSPK = 8I + 68µH

AVSPK_ = +8dB

f = 6000Hz

f = 1000Hz

f = 100Hz

THD+N RATIO (dB)

-70

-60

-50

-40

-30

-20

-10

-80

MAX9888 toc50

OUTPUT POWER (W)

0.80.60.40.20 1.0

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO SPEAKER)

f = 100Hz

VSPK_VDD = 3.7V

MCLK = 12.288MHz, LRCLK = 48kHz

NI MODE

ZSPK = 8I + 68µH

AVSPK_ = +8dB

f = 1000Hz

f = 6000Hz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO SPEAKER)

MAX9888 toc51

THD+N RATIO (dB)

-70

-60

-50

-40

-20

-30

-10

-80

OUTPUT POWER (W)

0.50.40.30.20.10 0.6

VSPK_VDD = 3.V

MCLK = 12.288MHz, LRCLK = 48kHz

NI MODE

ZSPK = 8I + 68µH

AVSPK_ = +8dB

f = 6000Hz

f = 1000Hz

f = 100Hz

VSPK_VDD = 4.2V

MCLK = 12.288MHz, LRCLK = 48kHz

NI MODE

ZSPK = 4I + 33µH

AVSPK_ = +8dB

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO SPEAKER)

MAX9888 toc52

OUTPUT POWER (W)

THD+N RATIO (dB)

2.01.51.00.50 2.5

-80

-70

-60

-50

-40

-30

-20

-10

-90

f = 6000Hz

f = 1000Hz

f = 100Hz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO SPEAKER)

VSPK_VDD = 3.7V

MCLK = 12.288MHz, LRCLK = 48kHz

NI MODE

ZSPK = 4I + 33µH

AVSPK_ = +8dB

MAX9888 toc53

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

OUTPUT POWER (W)

1.51.00.50 2.0

f = 6000Hz

f = 1000Hz

f = 100Hz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO SPEAKER)

MAX9888 toc54

OUTPUT POWER (W)

1.21.00.6 0.80.40.2

0 1.4

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

VSPK_VDD = 3V

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 4I + 33µH

AVSPK_ = +8dB

f = 6000Hz

f = 1000Hz

f = 100Hz

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

FREQUENCY (Hz)

10,0001000100

10 100,000

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (DAC TO SPEAKER)

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc55

VSPK_VDD = 4.2V

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 8I + 68µH

AVSPK_ = +8dB

POUT = 0.25W

POUT = 0.55W

FREQUENCY (Hz)

10,0001000100

10 100,000

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (DAC TO SPEAKER)

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc56

VSPK_VDD = 3.7V

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 8I + 68µH

AVSPK_ = +8dB

POUT = 0.25W

POUT = 0.55W

FREQUENCY (Hz)

10,0001000100

10 100,000

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (DAC TO SPEAKER)

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc57

VSPK_VDD = 4.2V

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 4I + 33µH

POUT = 0.5W

POUT = 1.0W

FREQUENCY (Hz)

10,0001000100

10 100,000

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (DAC TO SPEAKER)

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc58

VSPK_VDD = 3.7V

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 4I + 33µH

POUT = 0.5W

POUT = 1.0W

OUTPUT POWER vs. SUPPLY VOLTAGE

(DAC TO SPEAKER)

MAX9888 toc59

SUPPLY VOLTAGE (V)

OUTPUT POWER PER CHANNEL (mW)

5.04.54.03.53.0

600

800

1000

1200

1400

1600

1800

2000

2200

400

2.5 5.5

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 8I + 68µH

THD+N = 10%

THD+N = 10%THD+N = 10%

THD+N = 10%

THD+N = 1%

OUTPUT POWER vs. SUPPLY VOLTAGE

(DAC TO SPEAKER)

MAX9888 toc60

OUTPUT POWER PER CHANNEL (mW)

500

1000

1500

2000

2500

3000

3500

SUPPLY VOLTAGE (V)

5.04.54.03.53.02.5 5.5

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 4I + 33µH

THD+N = 10%

THD+N = 1%

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

GAIN vs. FREQUENCY

(DAC TO SPEAKER)

MAX9888 toc61

NORMALIZED GAIN (dB)

-4

-3

-2

-1

-5

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 8I + 68µH

FREQUENCY (Hz)

10,000100010010 100,000

EFFICIENCY (%)

100

EFFICIENCY vs. OUTPUT POWER

(DAC TO SPEAKER)

MAX9888 toc62

OUTPUT POWER PER CHANNEL (W)

0.5 1.0 1.5 2.00 2.5

VSPK_VDD = 4.2V

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

AVSPK_ = +8dB

ZSPK = 4I + 33µH

ZSPK = 8I + 68µH

EFFICIENCY vs. OUTPUT POWER

(DAC TO SPEAKER)

MAX9888 toc63

OUTPUT POWER PER CHANNEL (W)

1.4

1.20.8 1.00.4 0.60.20 1.6

EFFICIENCY (%)

100

VSPK_VDD = 3.7V

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

AVSPK_ = +8dB

ZSPK = 4I + 33µH

ZSPK = 8I + 68µH

SUPPLY CURRENT vs. SUPPLY VOLTAGE

(DAC TO SPEAKER)

MAX9888 toc64

SPK_VDD SUPPLY VOLTAGE (V)

SPK_VDD SUPPLY CURRENT (mA)

5.04.54.03.53.0

2.5 5.5

MCLK = 12.288MHz,

LRCLK = 48kHz

ZSPK = 8I + 68µH

NI MODE

AVSPK_ = +8dB

ALL ZEROS AT INPUT

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (DAC TO SPEAKER)

MAX9888 toc65

PSRR (dB)

-80

-60

-40

-20

-100

FREQUENCY (Hz)

10,000100010010 100,000

VRIPPLE = 200mVP-P

RIPPLE ON SPKLVDD,

SPKRVDD

RIPPLE ON AVDD,

DVDD, HPVDD

POWER-SUPPLY REJECTION RATIO

vs. SUPPLY VOLTAGE (DAC TO SPEAKER)

MAX9888 toc66

SUPPLY VOLTAGE (V)

5.0

4.54.03.53.02.5 5.5

PSRR (dB)

-80

-60

-40

-20

-100

RIPPLE ON SPKLVDD, SPKRVDD

VRIPPLE = 200mVP-P

f = 1kHz

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

FREQUENCY (Hz)

10,0001000100

10 100,000

CROSSTALK vs. FREQUENCY

(DAC TO SPEAKER)

CROSSTALK (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc67

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 8I + 68µH

SOFTWARE TURN-ON/OFF RESPONSE

(DAC TO SPEAKER, VSEN = 0)

MAX9888 toc68

SCL

2V/div

SPEAKER

OUTPUT

1V/div

10ms/div

SOFTWARE TURN-ON/OFF RESPONSE

(DAC TO SPEAKER, VSEN = 1)

MAX9888 toc69

SCL

2V/div

SPEAKER

OUTPUT

1V/div

10ms/div

FFT, -60dBFS (DAC TO SPEAKER)

MAX9888 toc70

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 12.288MHz,

LRCLK = 48kHz

NI MODE

ZSPK = 8I + 68µH

FFT, -60dBFS (DAC TO SPEAKER)

MAX9888 toc71

FREQUENCY (Hz)

AMPLITUDE (dbV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 13MHz,

LRCLK = 44.1kHz

PLL MODE

ZSPK = 8I + 68µH

WIDEBAND FFT

(DAC TO SPEAKER)

MAX9888 toc72

FREQUENCY (MHz)

AMPLITUDE (dBm)

-50

-40

-30

-20

-10

-60

1 100

MCLK = 13MHz,

LRCLK = 44.1kHz

PLL MODE

ZSPK = 8I + 68µH

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

Line to Speaker

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (LINE TO SPEAKER)

OUTPUT POWER (W)

0.80.60.2 0.4

MAX9888 toc73

THD+N RATIO (dB)

-70

-60

-50

-40

-20

-30

-10

-80

ZSPK = 8I + 68µH

AVSPK_ = +8dB

f = 6000Hz

f = 1000Hz f = 100Hz

FREQUENCY (Hz)

10,0001000100

10 100,000

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (LINE TO SPEAKER)

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc74

ZSPK = 8I + 68µH

CIN = 1µF

AVSPK_ = +8dB

POUT = 0.55W

POUT = 0.25W

GAIN vs. FREQUENCY

(LINE TO SPEAKER)

MAX9888 toc75

NORMALIZED GAIN (dB)

-4

-3

-2

-1

-5

FREQUENCY (Hz)

10,000100010010 100,000

ZSPK = 8I + 68µH

CIN = 1µF

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (LINE TO SPEAKER)

MAX9888 toc76

PSRR (dB)

-80

-60

-40

-20

-100

FREQUENCY (Hz)

10,000100010010 100,000

VRIPPLE = 200mVRMS

INPUT AC GROUNDED

RIPPLE ON AVDD,

DVDD, HPVDD

RIPPLE ON SPKLVDD,

SPKRVDD

FREQUENCY (Hz)

10,0001000100

10 100,000

CROSSTALK vs. FREQUENCY

(LINE TO SPEAKER)

CROSSTALK (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc77

ZSPK = 8I + 68µH

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

DAC to Headphone

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO HEADPHONE)

MAX9888 toc78

OUTPUT POWER (W)

THD+N RATIO (dB)

0.040.030.020.010 0.05

-80

-70

-60

-50

-40

-30

-20

-10

-90

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

RHP = 32I

AVHP_ = +3dB

f = 3000Hz

f = 100Hz

f = 1000Hz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO HEADPHONE)

MAX9888 toc79

OUTPUT POWER (W)

THD+N RATIO (dB)

0.040.030.020.010 0.05

-80

-70

-60

-50

-40

-30

-20

-10

-90

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

RHP = 32I

AVHP_ = +3dB

f = 6000Hz

f = 100Hz

f = 1000Hz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO HEADPHONE)

MAX9888 toc80

OUTPUT POWER (W)

THD+N RATIO (dB)

0.040.030.020.010 0.05

-80

-70

-60

-50

-40

-30

-20

-10

-90

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 32I

AVHP_ = +3dB

f = 6000Hz

f = 100Hz

f = 1000Hz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO HEADPHONE)

MAX9888 toc81

OUTPUT POWER (W)

THD+N RATIO (dB)

0.040.030.020.010 0.05

-80

-70

-60

-50

-40

-30

-20

-10

-90

MCLK = 12.288MHz

LRCLK = 96kHz

NI MODE

RHP = 32I

AVHP_ = +3dB

f = 6000Hz

f = 100Hz

f = 1000Hz

MAX9888 toc82

OUTPUT POWER (W)

0.070.060.04 0.050.02 0.030.010 0.08

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (DAC TO HEADPHONE)

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 16I

AVHP_ = +3dB

f = 6000Hz

f = 100Hz

f = 1000Hz

FREQUENCY (Hz)

1000100

10 10,000

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (LINE TO SPEAKER)

MAX9888 toc83

MCLK = 13MHz

LRCLK = 8kHz

FREQ MODE

RHP = 32I

AVHP_ = +3dB

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

POUT = 0.01W

POUT = 0.02W

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

FREQUENCY (Hz)

10,0001000100

10 100,000

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (DAC TO HEADPHONE)

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc84

POUT = 0.025W

POUT = 0.1W

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

RHP = 32I

AVHP_ = +3dB

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (DAC TO HEADPHONE)

MAX9888 toc85

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 100,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 32I

AVHP_ = +3dB

POUT = 0.025W

POUT = 0.01W

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (DAC TO HEADPHONE)

MAX9888 toc86

FREQUENCY (Hz)

THD+N RATIO (dB)

10,0001000100

-90

-80

-70

-60

-50

-40

-30

-20

-10

-100

10 100,000

MCLK = 12.288MHz

LRCLK = 96kHz

NI MODE

RHP = 32I

AVHP_ = +3dB

POUT = 0.025W

POUT = 0.01W

FREQUENCY (Hz)

10,0001000100

10 100,000

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (DAC TO HEADPHONE)

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc87

POUT = 0.01W

POUT = 0.0.25W

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 16I

GAIN vs. FREQUENCY

(DAC TO HEADPHONE)

MAX9888 toc88

NORMALIZED GAIN (dB)

-60

-50

-40

-30

-20

-10

-70

FREQUENCY (Hz)

10,000100010010 100,000

MCLK = 13MHz

LRCLK = 8kHz

NI MODE

RHP = 32I

MODE = 1

MODE = 0

HPVDD INPUT CURRENT vs. OUTPUT

POWER (DAC TO HEADPHONE)

MAX9888 toc89

OUTPUT POWER PER CHANNEL (mW)

HPVDD INPUT CURRENT (mA)

1010.1

100

120

0.01 100

RHP = 16I

RHP = 32I

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (DAC TO HEADPHONE)

MAX9888 toc90

PSRR (dB)

-80

-60

-40

-20

-100

FREQUENCY (Hz)

10,000100010010 100,000

VRIPPLE = 200mVP-P

INPUT ALL ZEROS

RIPPLE ON SPKLVDD,

SPKRVDD

RIPPLE ON AVDD,

DVDD, HPVDD

CROSSTALK vs. FREQUENCY

(DAC TO HEADPHONE)

MAX9888 toc91

CROSSTALK (dB)

-90

-80

-70

-60

-50

-40

-100

FREQUENCY (Hz)

10,000100010010 100,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 32I

SOFTWARE TURN-ON/OFF RESPONSE

(DAC TO HEADPHONE, VSEN = 0)

MAX9888 toc92

SCL

2V/div

HEADPHONE

OUTPUT

0.5V/div

10ms/div

SOFTWARE TURN-ON/OFF RESPONSE

(DAC TO HEADPHONE, VSEN = 1)

MAX9888 toc93

SCL

2V/div

HEADPHONE

OUTPUT

0.5V/div

10ms/div

FFT, 0dBFS (DAC TO HEADPHONE)

MAX9888 toc94

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 13MHz,

LRCLK = 8kHz

FREQ MODE

RHP = 32I

FFT, -60dBFS (DAC TO HEADPHONE)

MAX9888 toc95

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-140

-120

-100

-80

-60

-40

-20

-160

0 20,000

MCLK = 13MHz,

LRCLK = 8kHz

FREQ MODE

RHP = 32I

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

FFT, -60dBFS (DAC TO HEADPHONE)

MAX9888 toc97

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-140

-120

-100

-80

-60

-40

-20

-160

0 20,000

MCLK = 13MHz,

LRCLK = 44.1kHz

PLL MODE

RHP = 32I

FFT, 0dBFS (DAC TO HEADPHONE)

MAX9888 toc98

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 32I

FFT, 0dBFS (DAC TO HEADPHONE)

MAX9888 toc96

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 13MHz,

LRCLK = 44.1kHz

PLL MODE

RHP = 32I

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

FFT, 0dBFS (DAC TO HEADPHONE)

MAX9888 toc100

FREQUENCY (Hz)

AMPLITUDE (dbV)

15,00010,0005000

-120

-100

-80

-60

-40

-20

-140

0 20,000

MCLK = 12.288MHz

LRCLK = 96kHz

NI MODE

RHP = 32I

FFT, -60dBFS (DAC TO HEADPHONE)

MAX9888 toc101

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-140

-120

-100

-80

-60

-40

-20

-160

0 20,000

MCLK = 2.288MHz

LRCLK = 96kHz

NI MODE

RHP = 32I

WIDEBAND FFT, 0dBFS

(DAC TO HEADPHONE)

FREQUENCY (kHz)

AMPLITUDE (dBm)

1000100101

-80

-60

-40

-20

-100

0 10,000

MAX9888 toc102

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

AVHP_ = -3dB

RHP = 32I

FFT, -60dBFS (DAC TO HEADPHONE)

MAX9888 toc99

FREQUENCY (Hz)

AMPLITUDE (dBV)

15,00010,0005000

-140

-120

-100

-80

-60

-40

-20

-160

0 20,000

MCLK = 12.288MHz

LRCLK = 48kHz

NI MODE

RHP = 32I

WIDEBAND FFT, -60dBFS

(DAC TO HEADPHONE)

FREQUENCY (kHz)

AMPLITUDE (dBm)

1000100101

-80

-60

-40

-20

-100

0 10,000

MAX9888 toc103

MCLK = 13MHz

LRCLK = 44.1kHz

PLL MODE

AVHP_ = -3dB

RHP = 32I

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

Line to Headphone

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (LINE TO HEADPHONE)

OUTPUT POWER (W)

THD+N RATIO (dB)

0.040.030.01 0.02

-70

-60

-50

-40

-20

-30

-10

-80

0 0.05

MAX9888 toc104

RHP = 32I

AVHP_ = +3dB

f = 6000Hz

f = 100Hz

f = 1000Hz

FREQUENCY (Hz)

10,0001000100

10 100,000

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (LINE TO HEADPHONE)

THD+N RATIO (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc105

RHP = 32I

CIN = 1µF

POUT = 0.01W

POUT = 0.025W

GAIN vs. FREQUENCY

(LINE TO HEADPHONE)

MAX9888 toc106

NORMALIZED GAIN (dB)

-4

-3

-2

-1

-5

FREQUENCY (Hz)

10,000100010010 100,000

RHP = 32I

CIN = 1µF

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (LINE TO HEADPHONE)

MAX9888 toc107

PSRR (dB)

-80

-60

-40

-20

-100

FREQUENCY (Hz)

10,000100010010 100,000

VRIPPLE = 200mVP-P

RIPPLE ON SPKLVDD,

SPKRVDD

RIPPLE ON AVDD,

DVDD, HPVDD

FREQUENCY (Hz)

10,0001000100

10 100,000

CROSSTALK vs. FREQUENCY

(LINE TO HEADPHONE)

CROSSTALK (dB)

-80

-70

-60

-50

-40

-30

-20

-10

-90

MAX9888 toc108

RHP = 32I

COMMON-MODE REJECTION RATIO

vs. FREQUENCY (LINE TO HEADPHONE)

MAX9888 toc109

CMRR (dB)

FREQUENCY (Hz)

10,000100010010 100,000

VOUT = -6dBV

CIN = 1µF

RHP = 32I

AVPGAIN_ = 20dB

AVPGAIN_ = 0dB

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Typical Operating Characteristics (continued)

(VAVDD = VHPVDD = VDVDD = VDVDDS1 = VDVDDS2 = +1.8V, VSPKLVDD = VSPKRVDD = 3.7V. Speaker loads (ZSPK) connected

between SPK_P and SPK_N. Receiver load (RREC) connected between RECP and RECN. Headphone loads (RHP) connected from

HPL or HPR to GND. RHP = J, RREC = J, ZSPK = J, CREF = 2.2FF, CMICBIAS = CPREG = CREG = 1FF, CC1N-C1P = 1FF, CHPVSS

= 1FF. AVMICPRE_ = +20dB, AVMICPGA_ = 0dB, AVDACATTN = 0dB, AVDACGAIN = 0dB, AVADCLVL = 0dB, AVADCGAIN = 0dB,

AVPGAIN_ = 0dB, AVPGAOUT_ = 0dB, AVHP_ = 0dB, AVREC = 0dB, AVSPK_ = 0dB, MCLK = 12.288MHz, LRCLK = 48kHz, MAS =

1. TA = +25NC, unless otherwise noted.)

Speaker Bypass Switch

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

(SPEAKER BYPASS SWITCH)

OUTPUT POWER (W)

THD+N RATIO (dB)

0.15 0.200.100.05

-70

-60

-50

-40

-30

-20

-10

-80

MAX9888 toc110

RECEIVER AMPLIFIER DRIVING

LOUDSPEAKER

ZSPK = 8I + 68µH

f = 1000Hz

f = 100Hz

f = 6000Hz

ON RESISTANCE vs. VCOM

(SPEAKER BYPASS SWITCH)

MAX9888 toc111

VCOM (V)

RON (I)

541 2 3

0.5

1.0

1.5

2.0

2.5

3.0

3.5

ISW = 20mA

VSPK_VDD = 3.0V

VSPK_VDD = 3.7V

VSPK_VDD = 4.2V

VSPK_VDD = 5.0V

4.0

0 6

OFF-ISOLATION vs. FREQUENCY

(SPEAKER BYPASS SWITCH)

MAX9888 toc112

FREQUENCY (Hz)

OFF-ISOLATION (dB)

10,0001000100

-100

-80

-60

-40

-20

-120

10 100,000

SPEAKER AMP DRIVING LOUDSPEAKER

SPEAKER BYPASS SWITCH OPEN

MEASURED AT RXIN_

50I LOAD ON RXIN_

RECEIVER AMP DRIVING RXIN_

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Pin Configuration

TOP VIEW

(BUMP SIDE DOWN)

123456789

MAX9888

MCLK IRQ

SPKRVDD

SPKRVDD SDINS1

SPKLGNDSPKRP SPKLGND HPSNS

JACKSNS

SCLSDA REG

AVDDDVDD PREG

REF

AGND MICBIAS

SPKLVDD SPKLPSPKRGND SPKLN RECN/

RXINN

SPKLVDD SPKLP

SPKRGND SPKLN RECP/

RXINP HPVDD HPGND

SPKRP

DGND

SPKRN

HPR

HPL

HPVSS

C1P C1N

N.C. INB2

BCLKS1 LRCLKS1

N.C.

N.C.N.C.

N.C. INB1 INA2/

EXTMICN

DVDDS1 SDOUTS1 MIC1P/

DIGMICDATA

INA1/

EXTMICP

BCLKS2 LRCLKS2 MIC1N/

DIGMICCLK MIC2P

SDOUTS2 DVDDS2 SDINS2 MIC2N

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Pin Description

PIN NAME FUNCTION

A1, B1 SPKRN Negative Right-Channel Class D Speaker Output

A2, B2 SPKRGND Right-Speaker Ground

A3, B3 SPKLVDD Left-Speaker, REF, Receiver Amplifier Power Supply. Bypass to SPKLGND with a 1FF and a 10FF

capacitor.

A4, B4 SPKLP Positive Left-Channel Class D Speaker Output

A5, B5 SPKLN Negative Left-Channel Class D Speaker Output

A6 RECP/RXINP Positive Receiver Amplifier Output. Can be positive bypass switch input when receiver amp is shut

down.

A7 HPVDD Headphone Power Supply. Bypass to HPGND with a 1FF capacitor.

A8 HPGND Headphone Ground

A9 HPVSS Inverting Charge-Pump Output. Bypass to HPGND with a 1FF ceramic capacitor.

B6 RECN/RXINN Negative Receiver Amplifier Output. Can be negative bypass switch input when receiver amp is shut

down.

B7 C1P Charge-Pump Flying Capacitor Positive Terminal. Connect a 1FF ceramic capacitor between C1N

and C1P.

B8 C1N Charge-Pump Flying Capacitor Negative Terminal. Connect a 1FF ceramic capacitor between C1N

and C1P.

B9 HPL Left-Channel Headphone Output

C1, C2 SPKRP Positive Right-Channel Class D Speaker Output

C3, D3 SPKRVDD Right-Speaker Power Supply. Bypass to SPKRGND with a 1FF capacitor.

C4, C5 SPKLGND Left-Speaker Ground

C6 HPSNS Headphone Amplifier Ground Sense. Connect to the headphone jack ground terminal or connect to

ground.

C7, D5, D7,

E3, E6, E7 N.C. No Connection

C8 INB2 Single-Ended Line Input B2. Also positive differential line input B.

C9 HPR Right-Channel Headphone Output

D1 BCLKS1 S1 Digital Audio Bit Clock Input/Output. BCLKS1 is an input when the MAX9888 is in slave mode and

an output when in master mode. The input/output voltage is referenced to DVDDS1.

D2 LRCLKS1

S1 Digital Audio Left-Right Clock Input/Output. LRCLKS1 is the audio sample rate clock and

determines whether S1 audio data is routed to the left or right channel. In TDM mode, LRCLKS1 is a

frame sync pulse. LRCLKS1 is an input when the MAX9888 is in slave mode and an output when in

master mode. The input/output voltage is referenced to DVDDS1.

D4 SDINS1 S1 Digital Audio Serial-Data DAC Input. The input voltage is referenced to DVDDS1.

D6 JACKSNS Jack Sense. Detects the insertion of a jack. See the Headset Detection section.

D8 INB1 Single-Ended Line Input B1. Also negative differential line input B.

D9 INA2/

EXTMICN

Single-Ended Line Input A2. Also positive differential line input A or negative differential external

microphone input.

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Pin Description (continued)

PIN NAME FUNCTION

E1 DVDDS1 S1 Digital Audio Interface Power-Supply Input. Bypass to DGND with a 1FF capacitor.

E2 MCLK Master Clock Input. Acceptable input frequency range is 10MHz to 60MHz.

E4 SDOUTS1 S1 Digital Audio Serial-Data ADC Output. The output voltage is referenced to DVDDS1.

E5 IRQ

Hardware Interrupt Output. IRQ can be programmed to pull low when bits in status register 0x00

change state. Read status register 0x00 to clear IRQ once set. Repeat faults have no effect on IRQ

until it is cleared by reading the I2C status register 0x00. Connect a 10kI pullup resistor to DVDD for

full output swing.

E8 MIC1P/

DIGMICDATA

Positive Differential Microphone 1 Input. AC-couple a microphone with a series 1FF capacitor. Can

be retasked as a digital microphone data input.

E9 INA1/

EXTMICP

Single-Ended Line Input A1. Also negative differential line input A or positive differential external

microphone input.

F1 DGND Digital Ground

F2 BCLKS2 S2 Digital Audio Bit Clock Input/Output. BCLKS2 is an input when the IC is in slave mode and an

output when in master mode. The input/output voltage is referenced to DVDDS2.

F3 LRCLKS2

S2 Digital Audio Left-Right Clock Input/Output. LRCLKS2 is the audio sample rate clock and

determines whether audio data on S2 is routed to the left or right channel. In TDM mode, LRCLKS2 is

a frame sync pulse. LRCLKS2 is an input when the IC is in slave mode and an output when in master

mode. The input/output voltage is referenced to DVDDS2.

F4 SDA I2C Serial-Data Input/Output. Connect a pullup resistor to DVDD for full output swing.

F5 SCL I2C Serial-Clock Input

F6 REG Common-Mode Voltage Reference. Bypass to AGND with a 1FF capacitor.

F7 REF Converter Reference. Bypass to AGND with a 2.2FF capacitor.

F8 MIC1N/

DIGMICCLK

Negative Differential Microphone 1 Input. AC-couple a microphone with a series 1FF capacitor. Can

be retasked as a digital microphone clock output.

F9 MIC2P Positive Differential Microphone 2 Input. AC-couple a microphone with a series 1FF capacitor.

G1 SDOUTS2 S2 Digital Audio Serial-Data ADC Output. The output voltage is referenced to DVDDS2.

G2 DVDDS2 S2 Digital Audio Interface Power-Supply Input. Bypass to DGND with a 1FF capacitor.

G3 SDINS2 S2 Digital Audio Serial-Data DAC Input. The input voltage is referenced to DVDDS2.

G4 DVDD Digital Power Supply. Supply for the digital core and I2C interface. Bypass to DGND with a 1FF

capacitor.

G5 AVDD Analog Power Supply. Bypass to AGND with a 1FF capacitor.

G6 PREG Positive Internal Regulated Supply. Bypass to AGND with a 1FF capacitor.

G7 AGND Analog Ground

G8 MICBIAS Low-Noise Bias Voltage. Outputs a 2.2V microphone bias. An external resistor in the 2.2kI to 1kI

range should be used to set the microphone current.

G9 MIC2N Negative Differential Microphone 2 Input. AC-couple a microphone with a series 1FF capacitor.

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Detailed Description

The MAX9888 is a fully integrated stereo audio codec

with FlexSound technology and integrated amplifiers.

Two differential microphone amplifiers can accept sig-

nals from three analog inputs. One input can be retasked

to support two digital microphones. Any combination of

two microphones (analog or digital) can be recorded

simultaneously. The analog signals are amplified up

to 50dB and recorded by the stereo ADC. The digital

record path supports voice filtering with selectable

preset highpass filters and high stopband attenuation

at fS/2. An automatic gain control (AGC) circuit moni-

tors the digitized signal and automatically adjusts the

analog microphone gain to make best use of the ADC’s

dynamic range. A noise gate attenuates signals below

the user-defined threshold to minimize the noise output

by the ADC.

The IC includes two analog line inputs. One of the line

inputs can be optionally retasked as a third analog micro-

phone input. Both line inputs support either stereo single-

ended input signals or mono differential signals. The line

inputs are preamplified and then routed either to the ADC

for recording or to the output amplifiers for playback.

Integrated analog switches allow two differential micro-

phone signals to be routed out the third microphone

input to an external device. This eliminates the need

for an external analog switch in systems that have two

devices recording signals from the same microphone.

Through two digital audio interfaces, the device can

transmit one stereo audio signal and receive two stereo

audio signals in a wide range of formats including I2S,

PCM, and up to four mono slots in TDM. Each interface

can be connected to either of two audio ports (S1 and

S2) for communication with external devices. Both audio

interfaces support 8kHz to 96kHz sample rates. Each

input signal is independently equalized using 5-band

parametric equalizers. A multiband automatic level

control (ALC) boosts signals by up to 12dB. One signal

path additionally supports the same voiceband filtering

as the ADC path.

The IC includes a differential receiver amplifier, stereo

Class D speaker amplifiers, and DirectDrive true ground

stereo headphone amplifiers.

When the receiver amplifier is disabled, analog switches

allow RECP/RXINP and RECN/RXINN to be reused for

signal routing. In systems where a single transducer is

used for both the loudspeaker and receiver, an exter-

nal receiver amplifier can be routed to the left speaker

through RECP/RXINP and RECN/RXINN, bypassing the

Class D amplifier, to connect to the loudspeaker. If the

internal receiver amplifier is used, then leave RECP/

RXINP and RECN/RXINN unconnected. In systems

where an external amplifier drives both the receiver and

the MAX9888’s input, one of the differential signals can

be disconnected from the receiver when not needed

by passing it through the analog switch that connects

RECP/RXINP to RECN/RXINN.

The stereo Class D amplifier provides efficient amplifi-

cation for two speakers. The amplifier includes active

emissions limiting to minimize the radiated emissions

(EMI) traditionally associated with Class D. In most

systems, no output filtering is required to meet standard

EMI limits.

To optimize speaker sound quality, the IC includes an

excursion limiter, a distortion limiter, and a power limiter.

The excursion limiter is a dynamic highpass filter with

variable corner frequency that increases in response

to high signal levels. Low-frequency energy typically

causes more distortion than useful sound at high sig-

nal levels, so attenuating low frequencies allows the

speaker to play louder without distortion or damage. At

lower signal levels, the filter corner frequency reduces

to pass more low frequency energy when the speaker

can handle it. The distortion limiter reduces the volume

when the output signal exceeds a preset distortion level.

This ensures that regardless of input signal and battery

voltage, excessive distortion is never heard by the user.

The power limiter monitors the continuous power into the

loudspeaker and lowers the signal level if the speaker is

at risk of overheating.

The stereo DirectDrive headphone amplifier uses an

inverting charge pump to generate a ground-referenced

output signal. This eliminates the need for DC-blocking

capacitors or a midrail bias for the headphone jack

ground return. Ground sense reduces output noise

caused by ground return current.

The IC integrates jack detection allowing the detection

of insertion and removal of accessories as well as button

presses.

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 1. Register Map

I2C Slave Address

Configure the MAX9888 using the I2C control bus. The

IC uses a slave address of 0x20 or 00100000 for write

operations and 0x21 or 00100001 for read operations.

See the I2C Serial Interface section for a complete inter-

face description.

Registers

Table 1 lists all of the registers, their addresses, and

power-on-reset states. Registers 0x00 to 0x03 and 0xFF

are read-only while all of the other registers are read/

write. Write zeros to all unused bits in the register table

when updating the register, unless otherwise noted.

STATUS

Status CLD SLD ULK — — — JDET — 0x00 — R 103

Microphone

AGC/NG NG AGC 0x01 — R 65

Jack Status JKSNS — — — — — — 0x02 — R 101

Battery

Voltage — — — VBAT 0x03 — R/W 102

Interrupt

Enable ICLD ISLD IULK 0 0 0 IJDET 0 0x0F 0x00 R/W 103

MASTER CLOCK CONTROL

Master Clock 0 0 PSCLK 0 0 0 0 0x10 0x00 R/W 76

DAI1 CLOCK CONTROL

Clock Mode SR1 FREQ1 0x11 0x00 R/W 76

Any Clock

Control

PLL1 NI1[14:8] 0x12 0x00 R/W 77

NI1[7:1] NI1[0] 0x13 0x00 R/W 77

DAI1 CONFIGURATION

Format MAS1 WCI1 BCI1 DLY1 0 TDM1 FSW1 WS1 0x14 0x00 R/W 71

Clock OSR1 0 0 0 BSEL1 0x15 0x00 R/W 72

I/O

Configuration SEL1 LTEN1 LBEN1 DMONO1 HIZOFF1 SDOEN1 SDIEN1 0x16 0x00 R/W 72

Time-Division

Multiplex SLOTL1 SLOTR1 SLOTDLY1 0x17 0x00 R/W 73

Filters MODE1 AVFLT1 DHF1 DVFLT1 0x18 0x00 R/W 79

DAI2 CLOCK CONTROL

Clock Mode SR2 0 0 0 0 0x19 0x00 R/W 76

Any Clock

Control

PLL2 NI2[14:8] 0x1A 0x00 R/W 77

NI2[7:1] NI2[0] 0x1B 0x00 R/W 77

DAI2 CONFIGURATION

Format MAS2 WCI2 BCI2 DLY2 0 TDM2 FSW2 WS2 0x1C 0x00 R/W 71

Clock 0 0 0 0 0 BSEL2 0x1D 0x00 R/W 72

I/O

Configuration SEL2 0 LBEN2 DMONO2 HIZOFF2 SDOEN2 SDIEN2 0x1E 0x00 R/W 72

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 1. Register Map (continued)

Time-Division

Multiplex SLOTL2 SLOTR2 SLOTDLY2 0x1F 0x00 R/W 73

Filters 0 0 0 0 DHF2 0 0 DCB2 0x20 0x00 R/W 79

MIXERS

DAC Mixer MIXDAL MIXDAR 0x21 0x00 R/W 85

Left ADC

Mixer MIXADL 0x22 0x00 R/W 64

Right ADC

Mixer MIXADR 0x23 0x00 R/W 64

Preoutput 1

Mixer 0 0 0 0 MIXOUT1 0x24 0x00 R/W 86

Preoutput 2

Mixer 0 0 0 0 MIXOUT2 0x25 0x00 R/W 86

Preoutput 3

Mixer 0 0 0 0 MIXOUT3 0x26 0x00 R/W 86

Headphone

Amplifier

Mixer

MIXHPL MIXHPR 0x27 0x00 R/W 97

Receiver

Amplifier

Mixer

0 0 0 0 MIXREC 0x28 0x00 R/W 88

Speaker

Amplifier

Mixer

MIXSPL MIXSPR 0x29 0x00 R/W 90

LEVEL CONTROL

Sidetone DSTS 0 DVST 0x2A 0x00 R/W 69

DAI1

Playback

Level

DV1M 0 DV1G DV1 0x2B 0x00 R/W 84

DAI1

Playback

Level

0 0 0 EQCLP1 DVEQ1 0x2C 0x00 R/W 83

DAI2

Playback

Level

DV2M 0 0 0 DV2 0x2D 0x00 R/W 84

DAI2

Playback

Level

0 0 0 EQCLP2 DVEQ2 0x2E 0x00 R/W 83

Left ADC

Level 0 0 AVLG AVL 0x2F 0x00 R/W 68

Right ADC

Level 0 0 AVRG AVR 0x30 0x00 R/W 68

Microphone

1 Input Level 0 PA1EN PGAM1 0x31 0x00 R/W 61

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 1. Register Map (continued)

Microphone

2 Input Level 0 PA2EN PGAM2 0x32 0x00 R/W 61

INA Input

Level 0 INAEXT 0 0 0 PGAINA 0x33 0x00 R/W 63

INB Input

Level 0 INBEXT 0 0 0 PGAINB 0x34 0x00 R/W 63

Preoutput 1

Level 0 0 0 0 PGAOUT1 0x35 0x00 R/W 87

Preoutput 2

Level 0 0 0 0 PGAOUT2 0x36 0x00 R/W 87

Preoutput 3

Level 0 0 0 0 PGAOUT3 0x37 0x00 R/W 87

Left

Headphone

Amplifier

Volume

Control

HPLM 0 0 HPVOLL 0x38 0x00 R/W 97

Right

Headphone

Amplifier

Volume

Control

HPRM 0 0 HPVOLR 0x39 0x00 R/W 97

Receiver

Amplifier

Volume

Control

RECM 0 0 RECVOL 0x3A 0x00 R/W 88

Left Speaker

Amplifier

Volume

Control

SPLM 0 0 SPVOLL 0x3B 0x00 R/W 90

Right

Speaker

Amplifier

Volume

Control

SPRM 0 0 SPVOLR 0x3C 0x00 R/W 90

MICROPHONE AGC

Configuration AGCSRC AGCRLS AGCATK AGCHLD 0x3D 0x00 R/W 65

Threshold ANTH AGCTH 0x3E 0x00 R/W 66

SPEAKER SIGNAL PROCESSING

Excursion

Limiter Filter 0 DHPUCF 0 0 DHPLCF 0x3F 0x00 R/W 92

Excursion

Limiter

Threshold

0 0 0 0 0 DHPTH 0x40 0x00 R/W 92

ALC ALCEN ALCRLS ALCMB ALCTH 0x41 0x00 R/W 82

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 1. Register Map (continued)

Power Limiter PWRTH 0 PWRK 0x42 0x00 R/W 93

Power Limiter PWRT2 PWRT1 0x43 0x00 R/W 94

Distortion

Limiter THDCLP 0 THDT1 0x44 0x00 R/W 95

CONFIGURATION

Audio Input INADIFF INBDIFF 0 0 0 0 0 0 0x45 0x00 R/W 63

Microphone MICCLK DIGMICL DIGMICR 0 0 EXTMIC 0x46 0x00 R/W 61

Level Control VS2EN VSEN ZDEN 0 0 0 EQ2EN EQ1EN 0x47 0x00 R/W 99, 83

Bypass

Switches INABYP 0 0 MIC2BYP 0 0 RECBYP SPKBYP 0x48 0x00 R/W 62, 98

Jack

Detection JDETEN 0 0 0 0 0 JDEB 0x49 0x00 R/W 101

POWER MANAGEMENT

Input Enable INAEN INBEN 0 0 MBEN 0 ADLEN ADREN 0x4A 0x00 R/W 59

Output Enable HPLEN HPREN SPLEN SPREN RECEN 0 DALEN DAREN 0x4B 0x00 R/W 59

System

Enable SHDN VBATEN 0 0 0 0 JDWK 0 0x4C 0x00 R/W 59

DSP COEFFICIENTS

EQ Band 1

(DAI1/DAI2)

K_1[15:8] 0x50/0x82 0xXX R/W 82

K_1[7:0] 0x51/0x83 0xXX R/W 82

K1_1[15:8] 0x52/0x84 0xXX R/W 82

K1_1[7:0] 0x53/0x85 0xXX R/W 82

K2_1[15:8] 0x54/0x86 0xXX R/W 82

K2_1[7:0] 0x55/0x87 0xXX R/W 82

c1_1[15:8] 0x56/0x88 0xXX R/W 82

c1_1[7:0] 0x57/0x89 0xXX R/W 82

c2_1[15:8] 0x58/0x8A 0xXX R/W 82

c2_1[7:0] 0x59/0x8B 0xXX R/W 82

EQ Band 2

(DAI1/DAI2)

K_2[15:8] 0x5A/0x8C 0xXX R/W 82

K_2[7:0] 0x5B/0x8D 0xXX R/W 82

K1_2[15:8] 0x5C/0x8E 0xXX R/W 82

K1_2[7:0] 0x5D/0x8F 0xXX R/W 82

K2_2[15:8] 0x5E/0x90 0xXX R/W 82

K2_2[7:0] 0x5F/0x91 0xXX R/W 82

c1_2[15:8] 0x60/0x92 0xXX R/W 82

c1_2[7:0] 0x61/0x93 0xXX R/W 82

c2_2[15:8] 0x62/0x94 0xXX R/W 82

c2_2[7:0] 0x63/0x95 0xXX R/W 82

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 1. Register Map (continued)

EQ Band 3

(DAI1/DAI2)

K_3[15:8] 0x64/0x96 0xXX R/W 82

K_3[7:0] 0x65/0x97 0xXX R/W 82

K1_3[15:8] 0x66/0x98 0xXX R/W 82

K1_3[7:0] 0x67/0x99 0xXX R/W 82

K2_3[15:8] 0x68/0x9A 0xXX R/W 82

K2_3[7:0] 0x69/0x9B 0xXX R/W 82

c1_3[15:8] 0x6A/0x9C 0xXX R/W 82

c1_3[7:0] 0x6B/0x9D 0xXX R/W 82

c2_3[15:8] 0x6C/0x9E 0xXX R/W 82

c2_3[7:0] 0x6D/0x9F 0xXX R/W 82

EQ Band 4

(DAI1/DAI2)

K_4[15:8] 0x6E/0xA0 0xXX R/W 82

K_4[7:0] 0x6F/0xA1 0xXX R/W 82

K1_4[15:8] 0x70/0xA2 0xXX R/W 82

K1_4[7:0] 0x71/0xA3 0xXX R/W 82

K2_4[15:8] 0x72/0xA4 0xXX R/W 82

K2_4[7:0] 0x73/0xA5 0xXX R/W 82

c1_4[15:8] 0x74/0xA6 0xXX R/W 82

c1_4[7:0] 0x75/0xA7 0xXX R/W 82

c2_4[15:8] 0x76/0xA8 0xXX R/W 82

c2_4[7:0] 0x77/0xA9 0xXX R/W 82

EQ Band 5

(DAI1/DAI2)

K_5[15:8] 0x78/0xAA 0xXX R/W 82

K_5[7:0] 0x79/0xAB 0xXX R/W 82

K1_5[15:8] 0x7A/0xAC 0xXX R/W 82

K1_5[7:0] 0x7B/0xAD 0xXX R/W 82

K2_5[15:8] 0x7C/0xAE 0xXX R/W 82

K2_5[7:0] 0x7D/0xAF 0xXX R/W 82

c1_5[15:8] 0x7E/0xB0 0xXX R/W 82

c1_5[7:0] 0x7F/0xB1 0xXX R/W 82

c2_5[15:8] 0x80/0xB2 0xXX R/W 82

c2_5[7:0] 0x81/0xB3 0xXX R/W 82

Excursion

Limiter

Biquad

(DAI1/DAI2)

a1[15:8] 0xB4/0xBE 0xXX R/W 91

a1[7:0] 0xB5/0xBF 0xXX R/W 91

a2[15:8] 0xB6/0xC0 0xXX R/W 91

a2[7:0] 0xB7/0xC1 0xXX R/W 91

b0[15:8] 0xB8/0xC2 0xXX R/W 91

b0[7:0] 0xB9/0xC3 0xXX R/W 91

b1[15:8] 0xBA/0xC4 0xXX R/W 91

b1[7:0] 0xBB/0xC5 0xXX R/W 91

b2[15:8] 0xBC/0xC6 0xXX R/W 91

b2[7:0] 0xBD/0xC7 0xXX R/W 91

REVISION ID

Rev ID REV 0xFF 0x43 R 104

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Power Management

The IC includes comprehensive power management to allow the disabling of all unused circuits, minimizing supply

current.

Table 2. Power Management Registers

0x4C

7SHDN

Global Shutdown

Disables everything except the headset detection circuitry, which is controlled

separately.

0 = Device shutdown

1 = Device enabled

6 VBATEN See the Battery Measurement section.

1 JDWK See the Headset Detection section.

0x4A

7 INAEN

Line Input A Enable

0 = Disabled

1 = Enabled

6 INBEN

Line Input B Enable

0 = Disabled

1 = Enabled

3 MBEN

Microphone Bias Enable

0 = Disabled

1 = Enabled

1 ADLEN

Left ADC Enable

0 = Disabled

1 = Enabled

0 ADREN

Right ADC Enable

0 = Disabled

1 = Enabled

0x4B

7 HPLEN

Left Headphone Enable

0 = Disabled

1 = Enabled

6 HPREN

Right Headphone Enable

0 = Disabled

1 = Enabled

5 SPLEN

Left Speaker Enable

0 = Disabled

1 = Enabled

4 SPREN

Right Speaker Enable

0 = Disabled

1 = Enabled

3 RECEN

Receiver Enable

0 = Disabled

1 = Enabled

1 DALEN

Left DAC Enable

0 = Disabled

1 = Enabled

0 DAREN

Right DAC Enable

0 = Disabled

1 = Enabled

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Microphone Inputs

The device includes three differential microphone inputs

and a low-noise microphone bias for powering the micro-

phones (Figure 6). One microphone input can also be con-

figured as a digital microphone input accepting signals

from up to two digital microphones. Two microphones,

analog or digital, can be recorded simultaneously.

In the typical application, one microphone input is used

for the handset microphone and the other is used as an

accessory microphone. In systems using a background

noise microphone, INA can be retasked as another

microphone input.

In systems where the codec is not the only device

recording microphone signals, connect microphones to

MIC2P/MIC2N and EXTMICP/EXTMICN. MIC1P/MIC1N

then become outputs that route the microphone signals

to an external device as needed. Two devices can then

record microphone signals without needing external

analog switches.

Analog microphone signals are amplified by two stages

of gain and then routed to the ADCs. The first stage offers

selectable 0dB, 20dB, or 30dB settings. The second

stage is a programmable-gain amplifier (PGA) adjustable

from 0dB to 20dB in 1dB steps. To maximize the signal-

to-noise ratio, use the gain in the first stage whenever

possible. Zero-crossing detection is included on the PGA

to minimize zipper noise while making gain changes.

Figure 6. Microphone Input Block Diagram

MIC1P/

DIGMICDATA

MICBIAS

MBEN

MCLK

PSCLK

REG

MIC1N/

DIGMICCLK

MIC2BYP

INABYP

EXTMIC PA1EN:

0/20/30dB

PGAM1:

+20dB TO 0dB

MIX

MIXADL

MIXADR

ADCL

EXTMIC PA2EN:

0/20/30dB

PGAINA:

+20dB TO -6dB

PGAINA:

+20dB TO -6dB

MIC2P

MIC2N

INA1/EXTMICP

PGAM1:

+20dB TO 0dB

INADIFF

ADLEN

ADREN

INA2/EXTMICN

ADCR

CLOCK

CONTROL

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 3. Microphone Input Registers

0x31/0x32

PA1EN/PA2EN

MIC1/MIC2 Preamplifier Gain

Course microphone gain adjustment.

00 = Preamplifier disabled

01 = 0dB

10 = 20dB

11 = 30dB

PGAM1/PGAM2

MIC1/MIC2 PGA

Fine microphone gain adjustment.

VALUE GAIN (dB) VALUE GAIN (dB)

0x00 +20 0x0B +9

0x01 +19 0x0C +8

0x02 +18 0x0D +7

0x03 +17 0x0E +6

0x04 +16 0x0F +5

0x05 +15 0x10 +4

0x06 +14 0x11 +3

0x07 +13 0x12 +2

0x08 +12 0x13 +1

0x09 +11 0x14 to 0x1F 0

0x0A +10

0x46

MICCLK

Digital Microphone Clock Frequency

Select a frequency that is within the digital microphone’s clock frequency range.

Set OSR1 = 1 when using a digital microphone.

00 = PCLK/8

01 = PCLK/6

10 = 64 x LRCLK

11 = Reserved

5 DIGMICL

Left Digital Microphone Enable

Set PAL1EN = 00 for proper operation.

0 = Disabled

1 = Enabled

4 DIGMICR

Right Digital Microphone Enable

Set PAR1EN = 00 for proper operation.

0 = Disabled

1 = Enabled

EXTMIC

External Microphone Connection

Routes INA_/EXTMIC_ to the microphone preamplifiers. Set INAEN = 0 when using

INA_/EXTMIC_ as a microphone input.

00 = Disabled

01 = MIC1 input

10 = MIC2 input

11 = Reserved

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Line Inputs

The device includes two sets of line inputs (Figure 7).

Each set can be configured as a stereo single-ended

input or as a mono differential input. Each input includes

adjustable gain to match a wide range of input signal

levels. If a custom gain is needed, the external gain

mode provides a trimmed feedback resistor. Set the gain

by choosing the appropriate input resistor and using the

following formula:

AVPGAIN = 20 x log (20K/RIN)

The external gain mode also allows summing multiple

signals into a single input, by connecting multiple input

resistors as show in Figure 8, and inputting signals larger

than 1VP-P.

Table 3. Microphone Input Registers (continued)

Figure 7. Line Input Block Diagram Figure 8. Summing Multiple Input Signals into INA/INB

0x48

7 INABYP

INA_/EXTMIC_ to MIC1_ Bypass Switch

0 = Disabled

1 = Enabled

4 MIC2BYP

MIC1_ to MIC2_ Bypass Switch

0 = Disabled

1 = Enabled

1 RECBYP

See the Output Bypass Switches section.

0 SPKBYP

MIX

MIXOUT1

INADIFF

PGAINA:

+20dB TO -6dB

INABYP

INBDIFF

INA1/

EXTMICP

INA2/

EXTMICN

INB1

INB2

MIX

MIXOUT2

MIX

MIXOUT3

PGAINA:

+20dB TO -6dB

PGAINB:

+20dB TO -6dB

PGAINB:

+20dB TO -6dB

LEFT

INPUT 1

LEFT

INPUT 2 INA1/EXTMICP

VCM

INA2/EXTMICN

20kI

RIGHT

INPUT 1

RIGHT

INPUT 2

VCM

20kI

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ADC Input Mixers

The device’s stereo ADC accepts input from the micro-

phone amplifiers and line inputs. The ADC mixer routes

any combination of the six audio inputs to the left and

right ADCs (Figure 9).

Table 4. Line Input Registers

Figure 9. ADC Input Mixer Block Diagram

0x33/0x34

6 INAEXT/INBEXT

Line Input A/B External Gain

Switches out the internal input resistor and selects a trimmed 20kI feedback resistor.

Use an external input resistor to set the gain of the line input.

0 = Disabled

1 = Enabled

PGAINA/PGAINB

Line Input A/B Internal Gain Settings

000 = +20dB

001 = +14dB

010 = +3dB

011 = 0dB

100 = -3dB

101 = -6dB

110 = -6dB

111 = -6dB

0x45

7 INADIFF

Line Input A Differential Enable

0 = Stereo single-ended input

1 = Mono differential input

6 INBDIFF

Line Input B Differential Enable

0 = Stereo single-ended input

1 = Mono differential input

INBDIFF

PGAINB:

+20dB TO -6dB

PGAINB:

+20dB TO -6dB

INADIFF

PGAINA:

+20dB TO -6dB

PGAINA:

+20dB TO -6dB

PGAM2:

+20dB TO 0dB

PGAM1:

+20dB TO 0dB

MIXADR

ADREN

ADLEN

MIX

MIXADL

MIX

PA2EN:

0/20/30dB

PA1EN:

0/20/30dB

ADCR

ADCL

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 5. ADC Input Mixer Register

Figure 10. Record Path Signal Processing Block Diagram Figure 11. AGC and Noise Gate Input vs. Output Gain

Record Path Signal Processing

The device’s record signal path includes both automatic

gain control (AGC) for the microphone inputs and a digi-

tal noise gate at the output of the ADC (Figure 10).

Microphone AGC

The IC’s AGC monitors the signal level at the output of

the ADC and then adjusts the MIC1 and MIC2 analog

PGA settings automatically. When the signal level is

below the predefined threshold, the gain is increased up

to its maximum (20dB). If the signal exceeds the thresh-

old, the gain is reduced to prevent the output signal level

exceeding the threshold. When AGC is enabled, the

microphone PGA is not user programmable. The AGC

provides a more constant signal level and improves the

available ADC dynamic range.

Noise Gate

Since the AGC increases the levels of all signals below

a user-defined threshold, the noise floor is effectively

increased by 20dB. To counteract this, the noise gate

reduces the gain at low signal levels. Unlike typical noise

gates that completely silence the output below a defined

level, the noise gate in the IC applies downward expan-

sion. The noise gate attenuates the output at a rate of

1dB for each 2dB the signal is below the threshold.

The noise gate can be used in conjunction with the AGC

or on its own. When the AGC is enabled, the noise gate

reduces the output level only when the AGC has set the

gain to the maximum setting. Figure 11 shows the gain

response resulting from using the AGC and noise gate.

0x22/0x23

MIXADL/MIXADR

Left/Right ADC Input Mixer

Selects which analog inputs are recorded by the left/right ADC.

1xxxxxxx = MIC1

x1xxxxxx = MIC2

xx1xxxxx = Reserved

xxx1xxxx = Reserved

xxxx1xxx = INA1

xxxxx1xx = INA2 (INADIFF = 0) or INA2 - INA1 (INADIFF = 1)

xxxxxx1x = INB1

xxxxxxx1 = INB2 (INBDIFF = 0) or INB2 - INB1 (INBDIFF = 1)

PGAM2:

+20dB TO 0dB

PGAM1:

+20dB TO -6dB

MIXADR

ADREN

ADLEN

MIX

MIXADL

MIX

PA2EN:

0/20/30dB

PA1EN:

0/20/30dB

ADCR

ADCL

AVLG: 0/6/12/18dB

AVL: 3dB TO -12dB

MODE1

AVFLT

AVRG: 0/6/12/18dB

AVR: 3dB TO -2dB

AUTOMATIC

GAIN

CONTROL

NOISE GATE

AUDIO/

VOICE

FILTERS

AGC AND NOISE GATE

AMPLITUDE RESPONSE

INPUT AMPLITUDE (dBFS)

AGC ONLY

AGC AND NOISE GATE

NOISE GATE ONLY

AGC AND NOISE

GATE DISABLED

OUTPUT AMPLITUDE (dBFS)

-20-40-60-80-100

-120

-100

-80

-60

-40

-20

-120 0

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 6. Record Path Signal Processing Registers

0x01

Noise Gate Attenuation

Reports the current noise gate attenuation.

000 = 0dB

001 = 1dB

010 = 2dB

011 = 3dB to 5dB

100 = 6dB to 7dB

101 = 8dB to 9dB

110 = 10dB to 11dB

111 = 12dB

AGC

AGC Gain

Reports the current AGC gain setting.

VALUE GAIN (dB) VALUE GAIN (dB)

0x00 +20 0x0B +9

0x01 +19 0x0C +8

0x02 +18 0x0D +7

0x03 +17 0x0E +6

0x04 +16 0x0F +5

0x05 +15 0x10 +4

0x06 +14 0x11 +3

0x07 +13 0x12 +2

0x08 +12 0x13 +1

00x09 +11 0x14 to 0x1F 0

0x0A +10

0x3D

7 AGCSRC

AGC/Noise Gate Signal Source

Determines which ADC channel the AGC and noise gates analyze. Gain is adjusted on

both channels regardless of the AGCSRC setting.

0 = Left ADC output

1 = Maximum of either the left or right ADC output

AGCRLS

AGC Release Time

Defined as the duration from start to finish of gain increase in the region shown in Figure

12. Release times are longer for low AGC threshold levels.

000 = 78ms

001 = 156ms

010 = 312ms

011 = 625ms

100 = 1.25s

101 = 2.5s

110 = 5s

111 = 10s

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 6. Record Path Signal Processing Registers (continued)

0x3D

AGCATK

AGC Attack Time

Defined as the time required to reduce gain by 63% of the total gain reduction (one time

constant of the exponential response). Attack times are longer for low AGC threshold

levels. See Figure 12 for details.

00 = 2ms

01 = 7.2ms

10 = 31ms

11 = 123ms

AGCHLD

AGC Hold Time

The delay before the AGC release begins. The hold time counter starts whenever the

signal drops below the AGC threshold and is reset by any signal that exceeds the

threshold. Set AGCHLD to enable the AGC circuit. See Figure 12 for details.

00 = AGC disabled

01 = 50ms

10 = 100ms

11 = 400ms

0x3E

ANTH

Noise Gate Threshold

Gain is reduced for signals below the threshold to quiet noise. The thresholds are relative

to the ADC’s full-scale output voltage.

VALUE THRESHOLD

(dBFS) VALUE THRESHOLD

(dBFS)

0x0 Noise gate disabled 0x8 -45

0x1 Reserved 0x9 -41

0x2 Reserved 0xA -38

0x3 -64 0xB -34

0x4 -62 0xC -30

0x5 -58 0xD -27

0x6 -53 0xE -22

0x7 -50 0xF -16

AGCTH

AGC Threshold

Gain is reduced when signals exceed the threshold to prevent clipping. The thresholds

are relative to the ADC’s full-scale voltage.

VALUE THRESHOLD

(dBFS) VALUE THRESHOLD

(dBFS)

0x0 -3 0x8 -11

0x1 -4 0x9 -12

0x2 -5 0xA -13

0x3 -6 0xB -14

0x4 -7 0xC -15

0x5 -8 0xD -16

0x6 -9 0xE -17

0x7 -10 0xF -18

Stereo Audio CODEC

with FlexSound Technology

MAX9888

ADC Record Level Control

The IC includes separate digital level control for the left

and right ADC outputs (Figure 13). To optimize dynamic

range, use analog gain to adjust the signal level and set

the digital level control to 0dB whenever possible. Digital

level control is primarily used when adjusting the record

level for digital microphones.

Figure 12. AGC Timing

Figure 13. ADC Record Level Control Block Diagram

ATTACK TIME HOLD TIME RELEASE TIME

AUTOMATIC

GAIN CONTROL

NOISE GATE

MODE1

AVFLT1

AVLG: 0/6/12/18dB

AVL: 3dB TO -12dB

AVRG: 0/6/12/18dB

AVR: 3dB TO -2dB

ADREN

ADLEN

AUDIO/

VOICE

FILTERS

ADCR

ADCL

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 7. ADC Record Level Control Register

Figure 14. Sidetone Block Diagram

Sidetone

Enable sidetone during full-duplex operation to add a

low-level copy of the recorded audio signal to the play-

back audio signal (Figure 14). Sidetone is commonly

used in telephony to allow the speaker to hear himself

speak, providing a more natural user experience. The

IC implements sidetone digitally. Doing so helps prevent

unwanted feedback into the playback signal path and

better matches the playback audio signal.

0x2F/0x30

AVLG/AVRG

Left/Right ADC Gain

00 = 0dB

01 = 6dB

10 = 12dB

11 = 18dB

AVL/AVR

Left/Right ADC Level

VALUE GAIN (dB) VALUE GAIN (dB)

20x0 +3 0x8 -5

0x1 +2 0x9 -6

0x2 +1 0xA -7

0x3 0 0xB -8

0x4 -1 0xC -9

0x5 -2 0xD -10

0x6 -3 0xE -11

0x7 -4 0xF -12

ADREN

ADLEN

ADCR

ADCL

AVLG: 0/6/12/18dB

AVL: 3dB TO -12dB

MODE1

AVFLT

DSTS

SIDETONE

DVST:

0dB TO -60dB

AVRG: 0/6/12/18dB

AVR: 3dB TO -2dB

AUTOMATIC

GAIN

CONTROL

EQ1EN EQ2EN

DVEQ1:

0dB TO -15dB

DV1G:

0/6/12/18dB

DV2:

0dB TO -15dB DCB2

5-BAND

PARAMETRIC

5-BAND

PARAMETRIC

DVEQ2:

0dB TO -15dB

MULTIBAND ALC

EXCURSION LIMITER

DV1:

0dB TO -15dB MODE1

DVFLT

DALEN

MIXDAR

DACL

DAREN

DACR

NOISE GATE

MIX

MIXDAL

MIX

AUDIO/

FILTERS

AUDIO/

VOICE

FILTERS

AUDIO/

VOICE

FILTERS

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 8. Sidetone Register

Digital Audio Interfaces

The IC includes two separate playback signal paths and

one record signal path. Digital audio interface 1 (DAI1)

is used to transmit the recorded stereo audio signal and

receive a stereo audio signal for playback. Digital audio

interface 2 (DAI2) is used to receive a second stereo

audio signal. Use DAI1 for all full-duplex operations and

for all voice signals. Use DAI2 for music and to mix two

playback audio signals. The digital audio interfaces are

separate from the audio ports to enable either interface

to communicate with any external device connected to

the audio ports.

Each audio interface can be configured in a variety of

formats including left justified, I2S, PCM, and time divi-

sion multiplexed (TDM). TDM mode supports up to 4

mono audio slots in each frame. The IC can use up to

2 mono slots per interface, leaving the remaining two

slots available for another device. Table 9 shows how to

configure the device for common digital audio formats.

Figures 16 and 17 show examples of common audio

formats. By default, SDOUTS1 and SDOUTS2 are set

high impedance when the IC is not outputting data to

facilitate sharing the bus. Configure the interface in TDM

mode using only slot 1 to transmit and receive mono

PCM voice data.

The IC’s digital audio interfaces support both ADC to

DAC loop-through and digital loopback. Loop-through

allows the signal converted by the ADC to be routed

to the DAC for playback. The signal is routed from the

record path to the playback path in the digital audio

interface to allow the IC’s full complement of digital

signal processing to be used. Loopback allows digital

0x2A

DSTS

Sidetone Source

Selects which ADC output is fed back as sidetone. When mixing the left and right ADC

outputs, each is attenuated by 6dB to prevent full-scale signals from clipping.

00 = Sidetone disabled

01 = Left ADC

10 = Right ADC

11 = Left + Right ADC

DVST

Sidetone Level

Adjusts the sidetone signal level. All levels are referenced to the ADC’s full-scale output.

VALUE LEVEL (dB) VALUE LEVEL (dB)

0x00 Sidetone disabled 0x10 -30.5

0x01 -0.5 0x11 -32.5

0x02 -2.5 0x12 -34.5

0x03 -4.5 0x13 -36.5

0x04 -6.5 0x14 -38.5

0x05 -8.5 0x15 -40.5

0x06 -10.5 0x16 -42.5

0x07 -12.5 0x17 -44.5

0x08 -14.5 0x18 -46.5

0x09 -16.5 0x19 -48.5

0x0A -18.5 0x1A -50.5

0x0B -20.5 0x1B -52.5

0x0C -22.5 0x1C -54.5

0x0D -24.5 0x1D -56.6

0x0E -26.5 0x1E -58.5

0x0F -28.5 0x1F -60.5

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Figure 15. Digital Audio Signal Routing

Table 9. Common Digital Audio Formats

X = Don’t care.

data input to either SDINS1 or SDINS2 to be routed

from one interface to the other for output on SDOUTS2

or SDOUTS1. Both interfaces must be configured for

the same sample rate, but the interface format need

not be the same. This allows the IC to route audio data

from one device to another, converting the data format

as needed. Figure 15 shows the available digital signal

routing options.

MODE WCI1/WCI2 BCI1/BCI2 DLY1/DLY2 TDM1/TDM2 SLOTL1/SLOTL2 SLOTR1/SLOTR2

Left Justified Set as desired Set as desired 0 0 X X

I2S 1 0 1 0 X X

PCM X 1 X 1 0 0

TDM X 1 X 1 Set as desired

MAS1

DAI1

RECORD PATH

DAI1

PLAYBACK PATH

DAI2

PLAYBACK PATH

SEL1 SEL2

BCLK1

BCLKS1

LRCLK1

SDOUT1

SDIN1

LTEN1

LBEN2 +

BIT

CLOCK

FRAME

CLOCK

DATA

OUTPUT

DATA

INPUT

MAS1 HIZOFF1 MAS2

DAI2

BCLK2

LRCLK2

SDOUT2

SDIN2

BIT

CLOCK

FRAME

CLOCK

DATA

OUTPUT

DATA

INPUT

MAS2 HIZOFF2

LRCLKS1 SDOUTS1 SDINS1 DVDDS1 BCLKS2 LRCLKS2 SDOUTS2 SDINS2 DVDDS2

MUX

LBEN1

PORT S1 PORT S1

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 10. Digital Audio Interface Registers

0x14/0x1C

7 MAS1/MAS2

DAI1/DAI2 Master Mode

In master mode, DAI1/DAI2 outputs LRCLK and BCLK. In slave mode, DAI1/DAI2

accept LRCLK and BCLK as inputs.

0 = Slave mode

1 = Master mode

6 WCI1/WCI2

DAI1/DAI2 Word Clock Invert

TDM1/TDM2 = 0:

0 = Left-channel data is transmitted while LRCLK is low.

1 = Right-channel data is transmitted while LRCLK is low.

TDM1/TDM2 = 1:

Always set WCI = 0.

5 BCI1/BCI2

DAI1/DAI2 Bit Clock Invert

BCI1/BCI2 must be set to 1 when TDM1/TDM2 = 1.

0 = SDIN is accepted on the rising edge of BCLK.

SDOUT is valid on the rising edge of BCLK.

1 = SDIN is accepted on the falling edge of BCLK.

SDOUT is valid on the falling edge of BCLK.

Master Mode:

0 = LRCLK transitions on the falling edge of BCLK.

1 = LRCLK transitions on the rising edge of BCLK.

4 DLY1/DLY2

DAI1/DAI2 Data Delay

DLY1/DLY2 has no effect when TDM1/TDM2 = 1.

0 = The most significant data bit is clocked on the first active BCLK edge after an

LRCLK transition.

1 = The most significant data bit is clocked on the second active BCLK edge after an

LRCLK transition.

2 TDM1/TDM2

DAI1/DAI2 Time-Division Multiplex Mode (TDM Mode)

Set TDM1/TDM2 when communicating with devices that use a frame synchronization

pulse on LRCLK instead of a square wave.

0 = Disabled

1 = Enabled (BCI1/BCI2 must be set to 1)

1 FSW1/FSW2

DAI1/DAI2 Wide Frame Sync Pulse

Increases the width of the frame sync pulse to the full data width when TDM1/TDM2 =

1. FSW1/FSW2 has no effect when TDM1/TDM2 = 0.

0 = Disabled

1 = Enabled

0 WS1/WS2

DAI1/DAI2 Audio Data Bit Depth

Determines the maximum bit depth of audio being transmitted and received. Data is

always 16 bit when TDM1/TMD2 = 0.

0 = 16 bits

1 = 24 bits

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 10. Digital Audio Interface Registers (continued)

0x15/0x1D

OSR1

ADC Oversampling Ratio

Use the higher setting for maximum performance. Use the lower setting for reduced

power consumption at the expense of performance.

00 = 96x

01 = 64x

10 = Reserved

11 = Reserved

BSEL1/

BSEL2

DAI1/DAI2 BCLK Output Frequency

When operating in master mode, BSEL1/BSEL2 set the frequency of BCLK. When

operating in slave mode, BSEL1/BSEL2 have no effect. Select the lowest BCLK

frequency that clocks all data input to the DAC and output by the ADC.

000 = BCLK disabled

001 = 64 x LRCLK

010 = 48 x LRCLK

011 = 128 x LRCLK (invalid for DHF1/DHF2 = 1)

100 = PCLK/2

101 = PCLK/4

110 = PCLK/8

111 = PCLK/16

0x16/0x1E

SEL1/SEL2

DAI1/DAI2 Audio Port Selector

Selects which port is used by DAI1/DAI2.

00 = None

01 = Port S1

10 = Port S2

11 = Reserved

5 LTEN1

DAI1 Digital Loopthrough

Connects the output of the record signal path to the input of the playback path. Data

input to DAI1 from an external device is mixed with the recorded audio signal.

0 = Disabled

1 = Enabled

4LBEN1/

LBEN2

DAI1/DAI2 Digital Audio Interface Loopback

LBEN1 routes the digital audio input to DAI1 back out on DAI2. LBEN2 routes the

digital audio input to DAI2 back out on DAI1. Selecting LBEN2 disables the ADC

output data.

0 = Disabled

1 = Enabled

3DMONO1/

DMONO2

DAI1/DAI2 DAC Mono Mix

Mixes the left and right digital input to mono and routes the combined signal to the left

and right playback paths. The left and right input data is attenuated by 6dB prior to the

mono mix.

0 = Disabled

1 = Enabled

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 10. Digital Audio Interface Registers (continued)

0x16/0x1E

2HIZOFF1/

HIZOFF2

Disable DA1/DAI2 Output High-Impedance Mode

Normally SDOUT is set high impedance between data words. Set HIZOFF1/HIZOFF2 to

force a level on SDOUT at all times.

0 = Disabled

1 = Enabled

1SDOEN1/

SDOEN2

DAI1/DAI2 Record Path Output Enable

DAI2 outputs data only if LBEN1 = 1.

0 = Disabled

1 = Enabled

0SDIEN1/

SDIEN2

DAI1/DAI2 Playback Path Input Enable

0 = Disabled

1 = Enabled

0x17/0x1F

SLOTL1/

SLOTL2

TDM Left Time Slot

Selects which of the four slots is used for left data on DAI1/DAI2. If the same slot is

selected for left and right audio, left audio is placed in the slot.

00 = Slot 1

01 = Slot 2

10 = Slot 3

11 = Slot 4

SLOTR1/

SLOTR2

TDM Right Time Slot

Selects which of the four slots is used for right data on DAI1/DAI2. If the same slot is

selected for left and right audio, left audio is placed in the slot.

00 = Slot 1

01 = Slot 2

10 = Slot 3

11 = Slot 4

SLOTDLY1/

SLOTDLY2

TDM Slot Delay

Adds 1 BCLK cycle delay to the data in the specified TDM slot.

1xxx = Slot 4 delayed

x1xx = Slot 3 delayed

xx1x = Slot 2 delayed

xxx1 = Slot 1 delayed

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Figure 16. Non-TDM Data Format Examples

WCI_ = 0, BCI_ = 0, DLY_ = 0, TDM_ = 0, FSW_ = 0, WS_ = 0, HIZOFF_ = 1, SLOTL_ = 0, SLOTR_ = 0

LRCLK LEFT

LEFT

BCLK

SDOUT D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

RIGHT

SDIN

WCI_ = 1, BCI_ = 0, DLY_ = 0, TDM_ = 0, FSW_ = 0, WS_ = 0, HIZOFF_ = 1, SLOTL_ = 0, SLOTR_ = 0

LRCLK

BCLK

SDOUT

SDIN

LRCLK

BCLK

SDOUT

SDIN

WCI_ = 0, BCI_ = 1, DLY_ = 0, TDM_ = 0, FSW_ = 0, WS_ = 0, HIZOFF_ = 1, SLOTL_ = 0, SLOTR_ = 0

WCI_ = 0, BCI_ = 0, DLY_ = 1, TDM_ = 0, FSW_ = 0, WS_ = 0, HIZOFF_ = 1, SLOTL_ = 0, SLOTR_ = 0

LRCLK

BCLK

SDOUT

RIGHT

LEFT

SDIN

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Figure 17. TDM Mode Data Format Examples

LRCLK

BCLK

SDOUT

SDIN L15 L14 L13 L12 L11 L10 L9 L8 L7 L6 L5 L4 L3 L2 L1 L0 R15 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0

WCI_ = 0, BCI_ = 1, DLY_ = 0, TDM_ = 1, FSW_ = 0, WS_ = 0, HIZOFF_ = 0, SLOTL_ = 0, SLOTR_ = 1

L15 L14 L13 L12 L11 L10 L9 L8 L7 L6 L5 L4 L3 L2 L1 L0 R15 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 HI-Z

HI-Z

LRCLK

BCLK

SDOUT

SDIN

LRCLK

BCLK

SDOUT

SDIN

LRCLK

BCLK

SDOUT

SDIN

LRCLK

BCLK

SDOUT

SDIN L15 L14 L13 L12 L11 L10 L9 L8 L7 L6 L5 L4 L3 L2 L1 L0 R15 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0

WCI_ = 0, BCI_ = 1, DLY_ = 0, TDM_ = 1, FSW_ = 1, WS_ = 0, HIZOFF_ = 0, SLOTL_ = 0, SLOTR_ = 1

L15 L14 L13 L12 L11 L10 L9 L8 L7 L6 L5 L4 L3 L2 L1 L0 R15 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 HI-Z

HI-Z

L15 L14 L13 L12 L11 L10 L9 L8 L7 L6 L5 L4 L3 L2 L1 L0 R15 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0

WCI_ = 0, BCI_ = 1, DLY_ = 0, TDM_ = 1, FSW_ = 0, WS_ = 0, HIZOFF_ = 1, SLOTL_ = 0, SLOTR_ = 1

WCI_ = 0, BCI_ = 1, DLY_ = 0, TDM_ = 1, FSW_ = 0, WS_ = 0, HIZOFF_ = 0, SLOTL_ = 2, SLOTR_ = 3

L15 L14 L13 L12 L11 L10 L9 L8 L7 L6 L5 L4 L3 L2 L1 L0 R15 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 HI-Z

HI-Z

L15 L14 L13 L12 L11 L10 L9 L8 L7 L6 L5 L4 L3 L2 L1 L0 R15 R14 R13 R12 R11 R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0

32 CYCLES

L L L L L L L L R R R R R R R R

HI-Z

L L L L L L L L 1 1 1 1 R R R R

HI-Z

16 CYCLES 16 CYCLES 16 CYCLES 16 CYCLES

WCI_ = 0, BCI_ = 1, DLY_ = 0, TDM_ = 1, FSW_ = 0, WS_ = 0, HIZOFF_ = 0, SLOTL_ = 0, SLOTR_ = 1

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 11. Clock Control Registers

Clock Control

The digital signal paths in the IC require a master

clock (MCLK) between 10MHz and 60MHz to func-

tion. Internally, the MAX9888 requires a clock between

10MHz and 20MHz. A prescaler divides MCLK by 1, 2,

or 4 to create the internal clock (PCLK). PCLK is used to

clock all portions of the IC.

The MAX9888 includes two digital audio signal paths,

both capable of supporting any sample rate from 8kHz

to 96kHz. Each path is independently configured to allow

different sample rates. To accommodate a wide range

of system architectures, three main clocking modes are

supported:

U PLL Mode: When operating in slave mode, enable

the PLL to lock onto any LRCLK input. This mode

requires the least configuration, but provides the

lowest performance. Use this mode to simplify initial

setup or when normal mode and exact integer mode

cannot be used.

U Normal Mode: This mode uses a 15-bit clock divider

to set the sample rate relative to PCLK. This allows

high flexibility in both the PCLK and LRCLK frequen-

cies and can be used in either master or slave mode.

U Exact Integer Mode (DAI1 only): In both master and

slave modes, common MCLK frequencies (12MHz,

13MHz, 16MHz, and 19.2MHz) can be programmed

to operate in exact integer mode for both 8kHz and

16kHz sample rates. In these modes, the MCLK and

LRCLK rates are selected by using the FREQ1 bits

instead of the NI, and PLL control bits.

0x10

PSCLK

MCLK Prescaler

Generates PCLK, which is used by all internal circuitry.

00 = PCLK disabled

01 = 10MHz P MCLK P 20MHz (PCLK = MCLK)

10 = 20MHz P MCLK P 40MHz (PCLK = MCLK/2)

11 = 40MHz P MCLK P 60MHz (PCLK = MCLK/4)

0x11/0x19

SR1/SR2

DAI1/DAI2 Sample Rate

Used by the ALC to correctly set the dual-band crossover frequency and the excursion

limiter to set the predefined corner frequencies.

6VALUE SAMPLE RATE

(kHz) VALUE SAMPLE RATE

(kHz)

0x0 Reserved 0x8 48

0x1 8 0x9 88.2

0x2 11.025 0xA 96

0x3 16 0xB Reserved

0x4 22.05 0xC Reserved

0x5 24 0xD Reserved

0x6 32 0xE Reserved

0x7 44.1 0xF Reserved

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 11. Clock Control Registers (continued)

0x11

FREQ1

Exact Integer Mode

Overrides PLL1 and NI1 and configures a specific PCLK to LRCLK ratio.

VALUE SAMPLE RATE VALUE SAMPLE RATE

0x0 Disabled 0x8 PCLK = 12MHz,

LRCLK = 8kHz

0x1 Reserved 0x9 PCLK = 12MHz,

LRCLK = 16kHz

0x2 Reserved 0xA PCLK = 13MHz,

LRCLK = 8kHz

0x3 Reserved 0xB PCLK = 13MHz,

LRCLK = 16kHz

0x4 Reserved 0xC PCLK = 16MHz,

LRCLK = 8kHz

0x5 Reserved 0xD PCLK = 16MHz,

LRCLK = 16kHz

0x6 Reserved 0xE PCLK = 19.2MHz,

LRCLK = 8kHz

0x7 Reserved 0xF PCLK = 19.2MHz,

LRCLK = 16kHz

0x12/0x1A

7 PLL1/PLL2

PLL Mode Enable (Slave Mode Only)

PLL1/PLL2 enables a digital PLL that locks on to the externally supplied LRCLK

frequency and automatically sets the LRCLK divider (NI1/NI2).

0 = Disabled

1 = Enabled

NI1/

NI2

Normal Mode LRCLK Divider

When PLL1/PLL2 = 0, the frequency of LRCLK is determined by NI1/NI2. See Table 12

for common NI values.

3SAMPLE RATE DHF1/DHF2 NI1/NI2 FORMULA

18kHz P LRCLK P 48kHz 0

0x13/0x1B

48kHz < LRCLK P 96kHz 1

3fLRCLK = LRCLK frequency

fPCLK = Prescaled MCLK frequency (PCLK)

0 NI1[0]/NI2[0]

Rapid Lock Mode

Program NI1/NI2 to the nearest valid ratio and set NI1[0]/NI2[0] when PLL1/PLL2 = 1

to enable rapid lock mode. Normally, the PLL automatically calculates and dynamically

adjusts NI1/NI2. When rapid lock mode is properly configured, the PLL starting point is

much closer to the correct value, thus speeding up lock time. Wait one LRCLK period

after programming NI1/NI2 before setting PLL1/PLL2 = 1.

LRCLK

PCLK

65536 96 f

NI f

× ×

LRCLK

PCLK

65536 48 f

NI f

× ×

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 12. Common NI1/NI2 Values

Note: Values in bold are exact integers that provide maximum full-scale performance.

Figure 18. Digital Passband Filtering Block Diagram

Passband Filtering

Each digital signal path in the IC includes options for

defining the path bandwidth (Figure 18). The playback

and record paths connected to DAI1 support both voice

and music filtering while the playback path connected to

DAI2 supports music filtering only.

The voice IIR filters provide greater than 70dB stopband

attenuation at frequencies above fS/2 to reduce aliasing.

Three selectable highpass filters eliminate unwanted

low-frequency signals.

Use music mode when processing high-fidelity audio

content. The music FIR filters reduce power consump-

tion and are linear phase to maintain stereo imaging.

An optional DC-blocking filter is available to eliminate

unwanted DC offset.

In music mode, a second set of FIR filters are available

to support sample rates greater than 50kHz. The filters

can be independently selected for DAI1 and DAI2 and

support both the playback and record audio paths.

PCLK (MHz)

LRCLK (kHz)

DHF1/2 = 0 DHF1/2 = 1

8 11.025 12 16 22.05 24 32 44.1 48 64 88.2 96

10 13A9 1B18 1D7E 2752 3631 3AFB 4EA5 6C61 75F7 4EA5 6C61 75F7

11 11E0 18A2 1ACF 23BF 3144 359F 477E 6287 6B3E 477E 6287 6B3E

11.2896 116A 1800 1A1F 22D4 3000 343F 45A9 6000 687D 45A9 6000 687D

12 1062 1694 1893 20C5 2D29 3127 4189 5A51 624E 4189 5A51 624E

12.288 1000 160D 1800 2000 2C1A 3000 4000 5833 6000 4000 5833 6000

13 0F20 14D8 16AF 1E3F 29AF 2D5F 3C7F 535F 5ABE 3C7F 535F 5ABE

16 0C4A 10EF 126F 1893 21DE 24DD 3127 43BD 49BA 3127 43BD 49BA

16.9344 0B9C 1000 116A 1738 2000 22D4 2E71 4000 45A9 2E71 4000 45A9

18.432 0AAB 0EB3 1000 1555 1D66 2000 2AAB 3ACD 4000 2AAB 3ACD 4000

20 09D5 0D8C 0EBF 13A9 1B18 1D7E 2752 3631 3AFB 2752 3631 3AFB

ADREN

ADLEN

ADCR

ADCL

AVLG: 0/6/12/18dB

AVL: 3dB TO -12dB

MODE1

AVFLT

DSTS

SIDETONE

DVST:

0dB TO -60dB

AVRG: 0/6/12/18dB

AVR: 3dB TO -2dB

EQ1EN EQ2EN

DVEQ1:

0dB TO -15dB

DV1G:

0/6/12/18dB

DV2:

0dB TO -15dB DCB2

5-BAND

PARAMETRIC

5-BAND

PARAMETRIC

DVEQ2:

0dB TO -15dB

MULTIBAND ALC

EXCURSION LIMITER

DV1:

0dB TO -15dB MODE1

DVFLT

DALEN

MIXDAR

DACL

DAREN

DACR

MIX

MIXDAL

MIX

AUTOMATIC

GAIN

CONTROL

NOISE GATE

AUDIO/

VOICE

FILTERS

AUDIO/

FILTERS

AUDIO/

VOICE

FILTERS

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 13. Passband Filtering Registers

0x18

7 MODE1

DAI1 Passband Filtering Mode

0 = Voice filters

1 = Music filters (recommended for fS > 24kHz)

AVFLT1

DAI1 ADC Highpass Filter Mode

5MODE1 AVFLT1

40 See Table 14

1 Select a nonzero value to enable the DC-blocking filter

3 DHF1

DAI1 High Sample Rate Mode

Selects the sample rate range.

0 = 8kHz P LRCLK P 48kHz

1 = 48kHz P LRCLK < 96kHz

DVFLT1

DAI1 DAC Highpass Filter Mode

1MODE1 DVFLT1

00 See Table 14

1 Select a nonzero value to enable the DC-blocking filter

0x20

3 DHF2

DAI2 High Sample Rate Mode

Selects the sample rate range.

0 = 8kHz P LRCLK P 48kHz

1 = 48kHz < LRCLK P 96kHz

0 DCB2

DAI2 DC Blocking Filter

Enables a DC-blocking filter on the DAI2 playback audio path.

0 = Disabled

1 = Enabled

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 14. Voice Highpass Filters

AVFTL/DVFLT VALUE INTENDED SAMPLE RATE FILTER RESPONSE

000 N/A Disabled

001/011 16kHz/8kHz

010/100 16kHz/8kHz

101 8kHz to 48kHz

110/111 N/A Reserved

FREQUENCY (Hz)

AMPLITUDE (dB)

800600400200

-50

-40

-30

-20

-10

-60

0 1000

FREQUENCY (Hz)

AMPLITUDE (dB)

800600400200

-50

-40

-30

-20

-10

-60

0 1000

FREQUENCY (Hz)

AMPLITUDE (dB)

800600400200

-50

-40

-30

-20

-10

-60

0 1000

LRCLK = 48kHz

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Figure 20. ALC Input vs. Output ExamplesFigure 19. Playback Path Signal Processing Block Diagram

Playback Path Signal Processing

The IC playback signal path includes automatic level

control (ALC) and a 5-band parametric equalizer (EQ)

(Figure 19). The DAI1 and DAI2 playback paths include

separate ALCs controlled by a single set of registers.

Two completely separate parametric EQs are included

for the DAI1 and DAI2 playback paths.

Automatic Level Control

The automatic level control (ALC) circuit ensures maxi-

mum signal amplitude without producing audible clip-

ping. This is accomplished by a variable gain stage that

works on a sample by sample basis to increase the gain

up to 12dB. A look-ahead circuit determines if the next

sample exceeds full scale and reduces the gain so that

the sample is exactly full scale.

A programmable low signal threshold determines the

minimum signal amplitude that is amplified. Select a

threshold that prevents the amplification of background

noise. When the signal level drops below the low signal

threshold, the ALC reduces the gain to 0dB until the sig-

nal increases above the threshold. Figure 20 shows an

example of ALC input vs. output curves.

The ALC can optionally be configured in dual-band

mode. In this mode, the input signal is filtered into two

bands with a 5kHz center frequency. Each band is

routed through independent ALCs and then summed

together. In multiband mode, both bands use the same

parameters.

OUTPUT SIGNAL

(dBFS)

OUTPUT SIGNAL

(dBFS)

OUTPUT SIGNAL

(dBFS)

INPUT

SIGNAL

(dBFS)

INPUT

SIGNAL

(dBFS)

INPUT

SIGNAL

(dBFS)

LOW-LEVEL

THRESHOLD

-12 0

LOW-LEVEL

THRESHOLD

-12 0

LOW-LEVEL

THRESHOLD

-12 0

ALC WITH ALCTH ≠ 000

ALC WITH ALCTH = 000

ALC DISABLED

EQ1EN EQ2EN

DVEQ1:

0dB TO -15dB

DV1G:

0/6/12/18dB

DV2:

0dB TO -15dB DCB2

DVEQ2:

0dB TO -15dB

MULTIBAND ALC

EXCURSION LIMITER

DV1:

0dB TO -15dB MODE1

DVFLT

DALEN

MIXDAR

DACL

DAREN

DACR

MIX

MIXDAL

MIX

5-BAND

PARAMETRIC

5-BAND

PARAMETRIC

AUDIO/

FILTERS

AUDIO/

VOICE

FILTERS

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 15. Automatic Level Control Registers

Parametric Equalizer

The parametric EQ contains five independent biquad

filters with programmable gain, center frequency, and

bandwidth. Each biquad filter has a gain range of Q12dB

and a center frequency range from 20Hz to 20kHz. Use a

filter Q less than that shown in Figure 21 to achieve ideal

frequency responses. Setting a higher Q results in non-

ideal frequency response. The biquad filters are series

connected, allowing a total gain of Q60dB.

Figure 21. Maximum Recommended Filter Q vs. Frequency

0x41

7 ALCEN

ALC Enable

Enables ALC on both the DAI1 and DAI2 playback paths.

0 = Disabled

1 = Enabled

ALCRLS

ALC and Excursion Limiter Release Time

Sets the release time for both the ALC and Excursion Limiter. See the Excursion

Limiter section for Excursion Limiter release times. ALC release time is defined as the

time required to adjust the gain from 12dB to 0dB.

VALUE ALC RELEASE TIME (s)

000 8

001 4

010 2

011 1

100 0.5

101 0.25

110 Reserved

111 Reserved

3 ALCMB

Multiband Enable

Enables dual-band processing with a 5kHz center frequency. SR1 and SR2 must be

configured properly to achieve the correct center frequency for each playback path.

0 = Single-band ALC

1 = Dual-band ALC

ALCTH

Low Signal Threshold

Selects the minimum signal level to be boosted by the ALC.

000 = -JdB (low-signal threshold disabled)

001 = -12dB

010 = -18dB

011 = -24dB

100 = -30dB

101 = -36dB

110 = -42dB

111 = -48dB

CENTER FREQUENCY (Hz)

MAXIMUM RECOMMENDED FILTER Q

10,0001000

100

1000

0.1

100 100,000

fs = 8kHz

fs = 48kHz

fs = 96kHz

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 16. EQ Registers

Use the attenuator at the EQ’s input to avoid clipping

the signal. The attenuator can be programmed for fixed

attenuation or dynamic attenuation based on signal level.

If the dynamic EQ clip detection is enabled, the signal

level from the EQ is fed back to the attenuator circuit to

determine the amount of gain reduction necessary to

avoid clipping.

The MAX9888 EV kit software includes a graphic inter-

face for generating the EQ coefficients. The coefficients

are sample rate dependent and stored in registers 0x50

through 0xB3.

0x2C/0x2E

4EQCLP1/

EQCLP2

DAI1/DAI2 EQ Clip Detection

Automatically controls the EQ attenuator to prevent clipping in the EQ.

0 = Enabled

1 = Disabled

DVEQ1/DVEQ2

DAI1/DAI2 EQ Attenuator

Provides attenuation to prevent clipping in the EQ when full-scale signals are boost-

ed. DVEQ1/DVEQ2 operates only when EQ1EN/EQ2EN = 1 and EQCLP1/EQCLP2

= 1.

VALUE GAIN (dB) VALUE GAIN (dB)

0x0 0 0x8 -8

0x1 -1 0x9 -9

0x2 -2 0xA -10

0x3 -3 0xB -11

0x4 -4 0xC -12

0x5 -5 0xD -13

0x6 -6 0xE -14

0x7 -7 0xF -15

0x47

7VS2EN

See the Click-and-Pop Reduction section.

6VSEN

5ZDEN

1 EQ2EN

DAI2 EQ Enable

0 = Disabled

1 = Enabled

0 EQ1EN

DAI1 EQ Enable

0 = Disabled

1 = Enabled

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Figure 22. Playback Level Control Block Diagram

Table 17. DAC Playback Level Control Register

Playback Level Control

The IC includes separate digital level control for the DAI1

and DAI2 playback audio paths. The DAI1 signal path

allows boost when MODE1 = 0 and attenuation in any

mode. The DAI2 signal path allows attenuation only.

0x2B/0x2D

7 DV1M/DV2M

DAI1/DAI2 Mute

0 = Disabled

1 = Enabled

DV1G

DAI1 Voice Mode Gain

DV1G only applies when MODE1 = 0.

00 = 0dB

01 = 6dB

10 = 12dB

11 = 18dB

DV1/DV2

DAI1/DAI2 Attenuation

VALUE GAIN (dB) VALUE GAIN (dB)

0x0 0 0x8 -8

0x1 -1 0x9 -9

0x2 -2 0xA -10

0x3 -3 0xB -11

0x4 -4 0xC -12

0x5 -5 0xD -13

00x6 -6 0xE -14

0x7 -7 0xF -15

EQ1EN EQ2EN

DVEQ1:

0dB TO -15dB

DV1G:

0/6/12/18dB

DV2:

0dB TO -15dB DCB2

DVEQ2:

0dB TO -15dB

MULTIBAND ALC

EXCURSION LIMITER

DV1:

0dB TO -15dB MODE1

DVFLT

DALEN

MIXDAR

DACL

DAREN

DACR

MIX

MIXDAL

MIX

5-BAND

PARAMETRIC

5-BAND

PARAMETRIC

AUDIO/

FILTERS

AUDIO/

VOICE

FILTERS

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 18. DAC Input Mixer Register

Figure 23. DAC Input Mixer Block Diagram

DAC Input Mixers

The IC’s stereo DAC accepts input from two digital audio paths. The DAC mixer routes any audio path to the left and

right DACs (Figure 23).

0x21

MIXDAL

Left DAC Input Mixer

1xxx = DAI1 left channel

x1xx = DAI1 right channel

xx1x = DAI2 left channel

xxx1 = DAI2 right channel

MIXDAR

Right DAC Input Mixer

1xxx = DAI1 left channel

x1xx = DAI1 right channel

xx1x = DAI2 left channel

xxx1 = DAI2 right channel

EQ1EN EQ2EN

DVEQ1:

0dB TO -15dB

DV1G:

0/6/12/18dB

DV2:

0dB TO -15dB DCB2

5-BAND

PARAMETRIC

5-BAND

PARAMETRIC

DVEQ2:

0dB TO -15dB

MULTIBAND ALC

EXCURSION LIMITER

DV1:

0dB TO -15dB MODE1

DVFLT

DALEN

MIXDAR

DACL

DAREN

DACR

MIX

MIXDAL

MIX

AUDIO/

FILTERS

AUDIO/

VOICE

FILTERS

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Figure 24. Preoutput Signal Path Block Diagram

Table 19. Preoutput Mixer Registers

Preoutput Signal Path

The IC’s preoutput mixer stage provides mixing and level adjustment for line input signals routed to the output ampli-

fiers. Figure 24 shows a block diagram of the preoutput signal path. 9dB is added between the line input amplifiers

and the output amplifiers to boost the 1VP-P maximum line input signal level to the 1VRMS maximum DAC signal level.

Preoutput Mixer

The IC’s output amplifiers each accept input from one of the three preoutput mixers. Configure each pre-

output mixer to mix any combination of the four line input signals.

0x24/0x25/

0x26

MIXOUT1/

MIXOUT2/

MIXOUT3

Preoutput Mixer 1

1xxx = INA1

x1xx = INA2 (INADIFF = 0) or INA2 - INA1 (INADIFF = 1)

xx1x = INB1

xxx1 = INB2 (INBDIFF = 0) or INB2 - INB1 (INBDIFF = 1)

INBDIFF

MIXOUT3

MIXOUT2

PGAINB:

+20dB TO -6dB

MIX

PGAINB:

+20dB TO -6dB

INADIFF

PGAINA:

+20dB TO -6dB

PGAOUT1:

0dB TO -23dB

PGAOUT2:

0dB TO -23dB

PGAOUT3:

0dB TO -23dB

PGAINA:

+20dB TO -6dB

MIXOUT1

PREOUT1

MIX

PREOUT2

PREOUT3

+9dB

MIXREC

0dB

RECVOL:

+8dB TO -62dB

RECP/

RXINP

RECN/

RXINN

SPKLP

SPKLN

RECBYP

SPKBYP

RECEN

MIXSPL

+6dB

SPVOLL:

+8dB TO -62dB

SPKLVDD

SPKRP

SPKRN

SPLEN

SPREN

POWER/

DISTORTION LIMITER

MIXSPR

+6dB

SPVOLR:

+8dB TO -62dB HPVOLL:

+3dB TO -67dB

SPKLGND

SPKRVDD

SPKRPGND

HPL

HPSNS

HPR

HPLEN

MIXHPL

HPVOLR:

+3dB TO -67dB

HPREN

MIXHPR

MIX

BATTERY ADC

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 20. Preoutput PGA Registers

Figure 25. Receiver Amplifier Block Diagram

Preoutput PGA

The IC’s preoutput PGAs allow line input signals to be attenuated to match DAC output signal levels. Use the 0dB

setting for maximum performance.

Receiver Amplifier

The IC includes a single differential receiver amplifier. The receiver amplifier is designed to drive 32I receivers. In

cases where a single transducer is used for the loudspeaker and receiver, use the SPKBYP switch to route the receiver

amplifier output to the left speaker outputs.

0x35/0x36/

0x37

PGAOUT1/

PGAOUT2/

PGAOUT3

Preoutput PGA Level

VALUE GAIN (dB) VALUE GAIN (dB)

20x0 0 0x8 -15

0x1 -1 0x9 -17

0x2 -3 0xA -19

0x3 -5 0xB -21

0x4 -7 0xC -23

0x5 -9 0xD Mute

0x6 -11 0xE Mute

0x7 -13 0xF Mute

PGAOUT1:

0dB TO -23dB

PGAOUT2:

0dB TO -23dB

PREOUT1

PREOUT2

+9dB

DALEN

DACL

DAREN

DACR

MIXREC

0dB

RECVOL:

+8dB TO -62dB

RECP/

RXINP

RECN/

RXINN

RECBYP

SPKBYP

RECEN

MIX

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 21. Receiver Output Mixer Register

Table 22. Receiver Output Level Register

Receiver Output Mixer

The IC’s receiver amplifier accepts input from the stereo DAC and the line inputs. Configure the mixer to mix any combina-

tion of the available sources. When more than one signal is selected, the mixed signal is attenuated by 6dB for 2 signals,

9.5dB for 3 signals, or 12dB for 4 signals.

Receiver Output Volume

0x28

MIXREC

Receiver Output Mixer

1xxx = Left DAC

x1xx = Right DAC

xx1x = Preoutput mixer 1

xxx1 = Preoutput mixer 2

0x3A

7 RECM

Receiver Output Mute

0 = Disabled

1 = Enabled

RECVOL

Receiver Output Volume Level

VALUE VOLUME (dB) VALUE VOLUME (dB)

0x00 -62 0x10 -10

0x01 -58 0x11 -8

0x02 -54 0x12 -6

0x03 -50 0x13 -4

0x04 -46 0x14 -2

0x05 -42 0x15 0

0x06 -38 0x16 +1

0x07 -35 0x17 +2

0x08 -32 0x18 +3

0x09 -29 0x19 +4

0x0A -26 0x1A +5

0x0B -23 0x1B +6

0x0C -20 0x1C +6.5

0x0D -17 0x1D +7

0x0E -14 0x1E +7.5

0x0F -12 0x1F +8

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Speaker Amplifiers

The IC integrates a stereo filterless Class D amplifier that

offers much higher efficiency than Class AB without the

typical disadvantages.

The high efficiency of a Class D amplifier is due to the

switching operation of the output stage transistors. In a

Class D amplifier, the output transistors act as current

steering switches and consume negligible additional

power. Any power loss associated with the Class D out-

put stage is mostly due to the I2R loss of the MOSFET

on-resistance, and quiescent current overhead.

The theoretical best efficiency of a linear amplifier is

78%, however, that efficiency is only exhibited at peak

output power. Under normal operating levels (typical

music reproduction levels), efficiency falls below 30%,

whereas the IC’s Class D amplifier still exhibits 80% effi-

ciency under the same conditions.

Traditional Class D amplifiers require the use of exter-

nal LC filters or shielding to meet EN55022B and FCC

electromagnetic-interference (EMI) regulation standards.

Maxim’s patented active emissions limiting edge-rate

control circuitry reduces EMI emissions (Figure 26).

Figure 26. EMI with 15cm of Speaker Cable

Figure 27. Speaker Amplifier Path Block Diagram

300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000

30 60 80 100 120 140 160 180 200 220 240 260 280 300

-10

FREQUENCY (MHz)

AMPLITUDE (dBµV/m)

FREQUENCY (MHz)

AMPLITUDE (dBµV/m)

PGAOUT2:

0dB TO -23dB

PGAOUT3:

0dB TO -23dB

PREOUT2

PREOUT3

+9dB

DALEN

DACL

DAREN

DACR

SPKLP

SPKLN

MIXSPL

+6dB

SPVOLL:

+8dB TO -62dB

SPKLVDD

SPKLGND

SPKRVDD

SPKRP

SPKRN

SPLEN

SPREN

POWER/DISTORTION LIMITER

MIXSPR

+6dB

SPVOLR:

+8dB TO -62dB SPKRPGND

MIX

BATTERY ADC

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 23. Speaker Output Mixer Register

Table 24. Speaker Output Mixer Register

Speaker Output Mixers

The IC’s speaker amplifiers accept input from the stereo DAC and the line inputs. Configure the mixer to mix any combina-

tion of the available sources. When more than one signal is selected, the mixed signal is attenuated by 6dB for 2 signals,

9.5dB for 3 signals, or 12dB for four signals.

Speaker Output Volume

0x29

MIXSPL

Left Speaker Output Mixer

1xxx = Left DAC

x1xx = Right DAC

xx1x = Reserved

xxx1 = Preoutput mixer 3

MIXSPR

Right Speaker Output Mixer

1xxx = Left DAC

x1xx = Right DAC

xx1x = Reserved

xxx1 = Preoutput mixer 2

0x3B/0x3C

7 SPLM/SPRM

Left/Right Speaker Output Mute

0 = Disabled

1 = Enabled

SPVOLL/SPVOLR

Left/Right Speaker Output Volume Level

VALUE VOLUME (dB) VALUE VOLUME (dB)

0x00 -64 0x10 -10

0x01 -59 0x11 -8

0x02 -55 0x12 -6

0x03 -50 0x13 -4

0x04 -46 0x14 -2

0x05 -42 0x15 0

0x06 -38 0x16 +1

0x07 -35 0x17 +2

0x08 -32 0x18 +3

0x09 -29 0x19 +4

0x0A -26 0x1A +5

0x0B -23 0x1B +6

0x0C -20 0x1C +6.5

0x0D -17 0x1D +7

0x0E -14 0x1E +7.5

0x0F -12 0x1F +8

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Figure 28. Speaker Amplifier Signal Processing Block Diagram

Speaker Amplifier Signal Processing

The IC includes signal processing to improve the sound

quality of the speaker output and protect transducers

from damage. An excursion limiter dynamically adjusts

the highpass corner frequency, while a power limiter and

distortion limiter prevent the amplifier from outputting too

much distortion or power. The excursion limiter is located

in the DSP while the distortion limiter and power limiter

control the analog volume control (Figure 28). All three

limiters analyze the speaker amplifier’s output signal to

determine when to take action.

Excursion Limiter

The excursion limiter is a dynamic highpass filter that

monitors the speaker outputs and increases the high-

pass corner frequency when the speaker amplifier’s out-

put exceeds a predefined threshold. The filter smoothly

transitions between the high and low corner frequency to

prevent unwanted artifacts. The filter can operate in four

different modes:

U Fixed Frequency Preset Mode. The highpass corner

frequency is fixed at the upper corner frequency and

does not change with signal level.

U Fixed Frequency Programmable Mode. The high-

pass corner frequency is fixed to that specified by the

programmable biquad filter.

U Preset Dynamic Mode. The highpass filter automati-

cally slides between a preset upper and lower corner

frequency based on output signal level.

U User Programmable Dynamic Mode. The highpass

filter slides between a user-programmed biquad filter

on the low side to a predefined corner frequency on

the high side.

The transfer function for the user-programmable biquad is:

-1 -2

0 1 2

-1 -2

1 2

b b z b z

H(z)

1 a z a z

+ +

The coefficients b0, b1, b2, a1, and a2 are sample rate

dependent and stored in registers 0xB4 through 0xC7.

Store b0, b1, and b2 as positive numbers. Store a1 and

a2 as negated two’s complement numbers. Separate fil-

ters can be stored for the DAI1 and DAI2 playback paths.

The MAX9888 EV kit software includes a graphic interface

for generating the user-programmable biquad coefficients.

Note: Only change the excursion limiter settings when

the signal path is disabled to prevent undesired artifacts.

DALEN

DACL

DAREN

DACR

SPKLP

SPKLN

MIXSPL

+6dB

SPVOLL:

+8dB TO -62dB

SPKLVDD

SPKLGND

SPKRVDD

SPKRP

SPKRN

SPLEN

SPREN

POWER/

DISTORTION LIMITER

MIXSPR

+6dB

SPVOLR:

+8dB TO -62dB SPKRPGND

MIX

EQ1EN EQ2EN

DVEQ1:

0dB TO -15dB

DV1G:

0/6/12/18dB

DV2:

0dB TO -15dB DCB2

5-BAND

PARAMETRIC

5-BAND

PARAMETRIC

DVEQ2:

0dB TO -15dB

MULTIBAND ALC

EXCURSION LIMITER

DV1:

0dB TO -15dB MODE1

DVFLT

MIXDAR

MIX

MIXDAL

MIX

AUDIO/

FILTERS

AUDIO/

VOICE

FILTERS

BATTERY ADC

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 25. Excursion Limiter Registers

0x3F

DHPUCF

Excursion Limiter Corner Frequency

The excursion limiter has limited sliding range and minimum corner frequencies. Listed below

are all the valid filter combinations.

LOWER CORNER

FREQUENCY

UPPER CORNER

FREQUENCY

MINIMUM BIQUAD

CORNER FREQUENCY DHPUCF DHPLCF

Excursion limiter disabled — 000 00

400Hz — 001 00

600Hz — 010 00

800Hz — 011 00

1kHz — 100 00

DHPLCF

Programmable using biquad 100Hz 000 11

200Hz 400Hz — 001 01

400Hz 600Hz — 010 10

400Hz 800Hz — 011 10

Programmable

using biquad 400Hz 200Hz 001 11

Programmable

using biquad 600Hz 300Hz 010 11

Programmable

using biquad 800Hz 400Hz 011 11

Programmable

using biquad 1kHz 500Hz 100 11

0x41

ALCRLS

ALC and Excursion Limiter Release Time

Sets the release time for both the ALC and Excursion Limiter. See the Automatic Level Control

section for ALC release times. Excursion limiter release time is defined as the time required to

slide from the high corner frequency to the low corner frequency.

VALUE EXCURSION LIMITER RELEASE TIME (s)

000 4

001 2

010 1

011 0.5

100 0.25

101 0.25

110 Reserved

111 Reserved

0x40

DHPTH

Excursion Limiter Threshold

Measured at the Class D speaker amplifier outputs. Signals above the threshold use the upper

corner frequency. Signals below the threshold use the lower corner frequency. VBAT must

correctly reflect the voltage of SPKLVDD to achieve accurate thresholds.

000 = 0.34VP

001 = 0.71VP

010 = 1.30VP

011 = 1.77VP

100 = 2.33VP

101 = 3.25VP

110 = 4.25VP

111 = 4.95VP

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Power Limiter

The IC’s power limiter tracks the RMS power delivered to

the loudspeaker and briefly mutes the speaker amplifier

output if the speaker is at risk of sustaining permanent

damage.

Loudspeakers are typically damaged when the voice coil

overheats due to extended operation above the rated

power. During normal operation, heat generated in the

voice coil is transferred to the speaker’s magnet, which

transfers heat to the surrounding air. For the voice coil to

overheat, both the voice coil and the magnet must over-

heat. The result is that a loudspeaker can operate above

its rated power for a significant time before it heats suf-

ficiently to cause damage.

The IC’s power limiter includes user-programmable time

constants and power thresholds to match a wide range

of loudspeakers. Program the power limiter’s threshold to

match the loudspeaker’s rated power handling. This can

be determined through measurement or the loudspeak-

er’s specification. Program time constant 1 to match the

voice coil’s thermal time constant. Program time constant

2 to match the magnet’s thermal time constant. The time

constants can be determined by plotting the voice coil’s

resistance vs. time as power is applied to the speaker.

Table 26. Power Limiter Registers

0x42

PWRTH

Power Limiter Threshold

If the RMS output power from the speaker amplifiers exceeds this threshold, the out-

put is briefly muted to protect the speaker. The threshold is measured in watts assum-

ing an 8I load. VBAT must correctly reflect the voltage of SPKLVDD/SPKRVDD to

achieve accurate thresholds.

VALUE THRESHOLD

(W) VALUE THRESHOLD

(W)

0x0 Power limiter

disabled 0x8 0.27

0x1 0.05 0x9 0.35

0x2 0.06 0xA 0.48

0x3 0.09 0xB 0.72

0x4 0.11 0xC 1.00

0x5 0.13 0xD 1.43

0x6 0.18 0xE 1.57

0x7 0.22 0xF 1.80

PWRK

Power Limiter Weighting Factor

Determines the balance between time constant 1 and 2 to match the dominance of

each time constant in the loudspeaker.

VALUE T1 (%) T2 (%)

000 50 50

001 62.5 37.5

010 75 25

011 87.5 12.5

100 100 0

101 12.5 87.5

110 25 75

111 37.5 62.5

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Distortion Limiter

The IC’s distortion limiter ensures that the speaker amplifier’s output does not exceed the programmed THD+N limit.

The distortion limiter analyzes the Class D output duty cycle to determine the percentage of the waveform that is

clipped. If the distortion exceeds the programmed threshold, the output gain is reduced.

Table 26. Power Limiter Registers (continued)

0x43

PWRT2

Power Limiter Time Constant 2

Select a value that matches the thermal time constant of the loudspeaker’s magnet.

VALUE TIME CONSTANT

(min) VALUE TIME CONSTANT

(min)

0x0 Disabled 0x8 3.75

0x1 0.50 0x9 5.00

0x2 0.67 0xA 6.66

0x3 0.89 0xB 8.88

0x4 1.19 0xC Reserved

0x5 1.58 0xD Reserved

0x6 2.11 0xE Reserved

0x7 2.81 0xF Reserved

PWRT1

Power Limiter Time Constant 1

Select a value that matches the thermal time constant of the loudspeaker’s voice coil.

VALUE TIME CONSTANT

(s) VALUE TIME CONSTANT

(s)

0x0 Disabled 0x8 3.75

0x1 0.50 0x9 5.00

0x2 0.67 0xA 6.66

0x3 0.89 0xB 8.88

0x4 1.19 0xC Reserved

0x5 1.58 0xD Reserved

0x6 2.11 0xE Reserved

0x7 2.81 0xF Reserved

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Headphone Amplifier

The IC’s headphone amplifier integrates Maxim’s

DirectDrive architecture to eliminate the need for large

DC-blocking capacitors. Traditional single-supply head-

phone amplifiers have outputs biased at a nominal

DC voltage (typically half the supply). Large coupling

capacitors are needed to block this DC bias from the

headphone. Without these capacitors, a significant

amount of DC current flows to the headphone, resulting

in unnecessary power dissipation and possible damage

to both the headphone and headphone amplifier.

The DirectDrive architecture uses a charge pump to

create an internal negative supply voltage. This allows

the IC’s headphone outputs to be biased at GND while

operating from a single supply (Figure 29). Without a DC

component, there is no need for the large DC-blocking

capacitors. Instead of two large (220FF, typ) capaci-

tors, the IC charge pump requires two small ceramic

capacitors, conserving board space, reducing cost, and

improving the frequency response of the headphone

amplifier. There is a low DC voltage on the amplifier out-

puts due to amplifier offset. However, the offset of the IC

is typically Q0.2mV, which, when combined with a 32I

load, results in less than 6FA of DC current flow to the

headphones.

In addition to the cost and size disadvantages of

the DC-blocking capacitors required by conventional

headphone amplifiers, these capacitors limit the ampli-

fier’s low-frequency response and can distort the audio

signal. The DC-blocking capacitor not only blocks DC,

but also low-frequency audio. Improving the low-fre-

quency response of a conventional headphone amplifier

requires increasing the capacitor size, further adding

to the cost and size of the solution. Due to the voltage

coefficient of the capacitors used for DC blocking, they

introduce significant distortion near the corner frequency

of the highpass filter they create. This distortion further

degrades the low-frequency audio quality.

Table 27. Distortion Limiter Registers

0x44

THDCLP

Distortion Limit

Measured in % THD+N.

6VALUE THD+N LIMIT (%) VALUE THD+N LIMIT (%)

0x0 Limiter disabled 0x8 12

0x1 < 1 0x9 14

0x2 1 0xA 16

0x3 2 0xB 18

0x4 4 0xC 20

0x5 6 0xD 21

0x6 8 0xE 22

0x7 10 0xF 24

THDT1

Distortion Limiter Release Time Constant

Duration of time required for the speaker amplifier’s output gain to adjust back to the

nominal level after a large signal has passed.

000 = 6.2s

001 = 3.1s

010 = 1.6s

011 = 815ms

100 = 419ms

101 = 223ms

110 = 116ms

111 = 76ms

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Alternative approaches to eliminating the output-cou-

pling capacitors involve biasing the headphone return

(sleeve) to the DC bias voltage of the headphone ampli-

fiers. This method raises some issues:

U The sleeve is typically grounded to the chassis. Using

the midrail biasing approach, the sleeve must be

isolated from system ground, complicating product

design.

U During an ESD strike, the amplifier’s ESD structures

are the only path to system ground. Thus, the ampli-

fier must be able to withstand the full energy from an

ESD strike.

U When using the headphone jack as a line out to other

equipment, the bias voltage on the sleeve may con-

flict with the ground potential from other equipment,

resulting in possible damage to the amplifiers.

The IC features a low-noise charge pump to generate

a negative supply for the headphone amplifier. The

nominal switching frequency is well beyond the audio

range, and thus does not interfere with audio signals.

The switch drivers feature a controlled switching speed

that minimizes noise generated by turn-on and turn-off

transients. By limiting the switching speed of the charge

pump, the di/dt noise caused by the parasitic trace

inductance is minimized. The charge pump is active only

in headphone modes.

To reduce audible noise at the outputs, the IC’s head-

phone amplifier includes headphone ground sensing.

Connect the sense line (HPSNS) to the ground terminal

of the device’s headphone jack. Any noise present at

the headphone ground is then added to the headphone

output. The result is elimination of this noise from the

audible output. If ground sensing is not required, con-

nect HPSNS directly to ground. Figure 30 shows a block

diagram of the headphone output section including the

headphone sense function.

Headphone Output Mixers

The IC’s headphone amplifier accepts input from the

stereo DAC and the line inputs. The output of the left and

right DAC cannot be mixed at the headphone mixer. Use

MIXDAL/MIXDAR to mix the left and right audio channels

before conversion.

Figure 29. Traditional Amplifier Output vs. DirectDrive Output Figure 30. Headphone Amplifier Block Diagram

VDD

VDD/2

GND

CONVENTIONAL AMPLIFIER BIASING SCHEME

DirectDrive AMPLIFIER BIASING SCHEME

+VDD

GND

-VDD

(VSS)

MIXHPL

MIXHPR

MIX

PGAOUT2:

0dB TO -23dB

HPVOLL:

+3dB TO -67dB

HPVOLR:

+3dB TO -67dB

PREOUT2 +9dB

PGAOUT1:

0dB TO -23dB

DAREN

HPL

HPSNS

HPLEN

HPREN

HPR

PREOUT1 +9dB

DACR

DALEN

DACL

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Table 28. Headphone Output Mixer Register

Table 29. Headphone Output Level Register

Headphone Output Volume

0x27

MIXHPL

Left Headphone Output Mixer

10xx = Left DAC

01xx = Right DAC (requires DALEN = 0 for proper operation)

11xx = Left DAC

xx1x = Reserved

xxx1 = Preoutput mixer 1

MIXHPR

Right Headphone Output Mixer

10xx = Left DAC (requires DAREN = 0 for proper operation)

01xx = Right DAC

11xx = Right DAC

xx1x = Reserved

xxx1 = Preoutput mixer 2

0x38/0x39

7 HPLM/HPRM

Headphone Output Mute

0 = Disabled

1 = Enabled

HPVOLL/HPVOLR

Left/Right Headphone Output Volume Level

VALUE VOLUME (dB) VALUE VOLUME (dB)

0x00 -67 0x10 -15

0x01 -63 0x11 -13

0x02 -59 0x12 -11

0x03 -55 0x13 -9

0x04 -51 0x14 -7

0x05 -47 0x15 -5

0x06 -43 0x16 -4

0x07 -40 0x17 -3

0x08 -37 0x18 -2

0x09 -34 0x19 -1

0x0A -31 0x1A 0

0x0B -28 0x1B +1

0x0C -25 0x1C +1.5

0x0D -22 0x1D +2

0x0E -19 0x1E +2.5

0x0F -17 0x1F +3

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Output Bypass Switches

The IC includes two output bypass switches that solve

common applications problems. When a single trans-

ducer is used for the loudspeaker and receiver, the need

exists for two amplifiers to power the same transducer.

Bypass switches connect the IC’s receiver amplifier

output to the speaker amplifier’s output, allowing either

amplifier to power the same transducer. In systems where

an external receiver amplifier is used, route its output to

the left speaker through RECP/RXINP and RECN/RXINN,

bypassing the Class D amplifier. In systems where an

external amplifier drives both the receiver and the IC’s

line input, one of the differential signals can be discon-

nected from the receiver when not needed by passing it

through the analog switch that connects RECP/RXINP to

RECN/RXINN.

Figure 31. Output Bypass Switch Block Diagrams

Table 30. Output Bypass Switches Register

0x48

7 INABYP See the Microphone Inputs section.

4 MIC2BYP

1 RECBYP

RXINP to RXINN Bypass Switch

Shorts RXINP to RXINN allowing a signal to pass through the MAX9888. Disable the

receiver amplifier when RECBYP = 1.

0 = Disabled

1 = Enabled

0 SPKBYP

RXIN to SPKL Bypass Switch

Shorts RXINP/RXINN to SPKLP/SPKLN allowing either the internal or an external

receiver amplifier to power the left speaker. Disable the left speaker amplifier when

SPKBYP = 1.

0 = Disabled

1 = Enabled

EXTERNAL

RECEIVER

AMP

RECP/RXINP

RECEN

SPLEN

POWER/DISTORTION

LIMITER

RECBYP

SPKBYP

10I*

RECN/RXINN

SPKLVDD

SPKLP

SPKLN

0dB

SPKLGND

+6dB

*OPTIONAL 10I RESISTORS IMPROVE DISTORTION

THROUGH THE ANALOG SWITCH.

SPEAKER AMPLIFIER BYPASS USING AN

EXTERNAL RECEIVER AMPLIFIER

SPEAKER AMPLIFIER BYPASS USING THE

INTERNAL RECEIVER AMPLIFIER CONTROLLING AN EXTERNAL RECEIVE

AMPLIFIER AND SPEAKER

EXTERNAL

RECEIVER AMP

RECN/RXINN

RECEN

SPLEN

POWER/DISTORTION

LIMITER

RECBYP

SPKBYP

RECN/RXINN

SPKLVDD

SPKLP

SPKLN

0dB

SPKLGND

+6dB

RECP/RXINP

RECEN

SPLEN

POWER/DISTORTION

LIMITER

RECBYP

SPKBYP

RECN/RXINN

SPKLVDD

SPKLP

SPKLN

0dB

SPKLGND

+6dB

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Click-and-Pop Reduction

The IC includes extensive click-and-pop reduction cir-

cuitry. The circuitry minimizes clicks and pops at turn-on,

turn-off, and during volume changes.

Zero-crossing detection is implemented on all analog

PGAs and volume controls to prevent large glitches

when volume changes are made. Instead of making a

volume change immediately, the change is made when

the audio signal crosses the midpoint. If no zero-crossing

occurs within the timeout window, the change is forced.

Volume slewing breaks up large volume changes into the

smallest available step size and the steps through each

step between the initial and final volume setting. When

enabled, volume slewing also occurs at device turn-on

and turn-off. During turn-on the volume is set to mute

before the output is enabled. Once the output is on, the

volume ramps to the desired level. At turn-off the volume

is ramped to mute before the outputs are disabled.

When there is no audio signal zero-crossing detection

can prevent volume slewing from occurring. Enable

enhanced volume slewing to prevent the volume control-

ler from requesting another volume level until the previ-

ous one has been set. Each step in the volume ramp

then occurs after a zero crossing has occurred in the

audio signal or the timeout window has expired. During

turn-off, enhance volume slewing is always disabled.

Table 31. Click-and-Pop Reduction Register

0x49

7VS2EN

Enhanced Volume Smoothing

During volume slewing, the controller waits for each step in the ramp to be applied

before sending the next step. When zero-crossing detection is enabled this prevents

large steps in the output volume when no zero crossings are detected.

0 = Enabled

1 = Disabled

Applies to volume changes in HPVOLL, HPVOLR, RECVOL, SPVOLL, and SPVOLR.

6VSEN

Volume Adjustment Smoothing

Volume changes are smoothed by stepping through intermediate steps. Also ramps

the volume from minimum to the programmed value at turn-on and back to minimum at

turn-off.

0 = Enabled

1 = Disabled

Applies to volume changes in HPVOLL, HPVOLR, RECVOL, SPVOLL, and SPVOLR.

5ZDEN

Zero-Crossing Detection

Holds volume changes until there is a zero crossing in the audio signal. This reduces

click and pop during volume changes (zipper noise). If no zero crossing is detected

within 100ms, the volume change is forced.

0 = Enabled

1 = Disabled

Applies to volume changes in PGAM1, PGAM2, PGAOUTA, PGAOUTB, PGAOUTC,

HPVOLL, HPVOLR, RECVOL, SPVOLL, and SPVOLR.

1 EQ2EN See the 5-Band Parametric EQ section.

0 EQ1EN

Stereo Audio CODEC

with FlexSound Technology

MAX9888

100

Jack Detection

The IC features jack detection that can detect the inser-

tion and removal of a jack as well as the load type. When

a jack is detected, an interrupt on IRQ can be triggered

to alert the microcontroller of the event. Figure 32 shows

the typical configuration for jack detection.

Jack Insertion

To detect a jack insertion, the IC must have a power

supply and MICBIAS should be disabled. Set JDETEN

to enable jack detection circuitry and apply a pullup cur-

rent to JACKSNS. Set JDWK to minimize supply current.

Clear JDWK to differentiate between headsets with a

microphone and headphones without a microphone. The

voltage on JACKSNS is equal to SPKLVDD as long as no

load is applied to JACKSNS. Table 32 shows the change

in JKSNS that occurs when a jack is inserted.

Accessory Button Detection

After jack insertion, the MAX9888 can detect button

presses on accessories that include a microphone and

a switch that shorts the microphone signal to ground.

Set JDETEN to enable jack detection circuitry. A pullup

current is automatically applied to JACKSNS if MICBIAS

is disabled. Clear JDWK to allow differentiation between

the microphone load and a short to ground. Button

presses can be detected both when MICBIAS is enabled

and disabled. Table 33 shows the change in JKSNS that

occurs when the accessory button is pressed.

Figure 32. Typical Configuration for Jack Detection

Table 32. Change in JKSNS Upon Jack Insertion

Table 33. Change in JKSNS Upon Button Press

JACK TYPE JDWK = 1 JDWK = 0

JKSNS: 11 è 00 JKSNS: 11 è 00

JKSNS: 11 è 00 JKSNS: 11 è 01

JACK TYPE MICBIAS ENABLED OR DISABLED

JKSNS: 01 è 00

HPL MICBIAS

JACKSNS

MIC1P

HPR

GND GND R L

MIC GND R L

Stereo Audio CODEC

with FlexSound Technology

MAX9888

101

Jack Removal

The IC detects jack removal by monitoring JACKSNS

for transitions to the 11 state. Set JDETEN to enable

jack detection circuitry. A pullup current is automatically

applied to JACKSNS if MICBIAS is disabled. Set JDWK

to minimize supply current if button detection is not

required. Table 34 shows the change in JKSNS that

occurs when a jack is removed.

Table 34. Change in JKSNS Upon Jack Removal

Table 35. Jack Detection Registers

JACK TYPE JDWK = 1 AND MICBIAS DISABLED JDWK = 0 OR MICBIAS ENABLED

JKSNS: 00 è 11 JKSNS: 00 è 11

JKSNS: 00 è 11 JKSNS: 01 è 11

0x02

(Read Only)

JKSNS

JACKSNS State

Reports the status of JACKSNS when JDETEN = 1.

VALUE MODE DESCRIPTION

00 MBEN = 1 VJACKSNS < 0.1 x VMICBIAS

MBEN = 0 VJACKSNS < 0.1 x VSPKLVDD

01 MBEN = 1 0.1 x VMICBIAS < VJACKSNS < 0.95 x VMICBIAS

MBEN = 0 0.1 x VSPKLVDD < VJACKSNS < 0.95 x VSPKLVDD

10 MBEN = 1 Reserved

MBEN = 0 Reserved

11 MBEN = 1 0.95 x VMICBIAS < VJACKSNS

MBEN = 0 0.95 x VSPKLVDD < VJACKSNS

0x49

7 JDETEN

Jack Detection Enable

0 = Disabled

1 = Enabled

JDEB

Jack Detection Debounce

Configures the debounce time for setting JDET.

00 = 25ms

01 = 50ms

10 = 100ms

11 = 200ms

0x4C

7SHDN See the Power Management section.

6 VBATEN See the Battery Measurement section.

1 JDWK

JACKSNS Pullup

When JDWK = 1 JACKSNS is slow to increase in voltage. Set JDWK = 0 before setting

JDETEN = 1 to prevent false detection.

Valid when MBIAS = 0 or SHDN = 0.

0 = 2.4kI to SPKLVDD (allows microphone detection)

1 = 5FA to SPKLVDD (minimizes supply current)

GND GND R L

MIC GND R L

Stereo Audio CODEC

with FlexSound Technology

MAX9888

102

Battery Measurement

The IC measures the voltage applied to SPKLVDD (typi-

cally the battery voltage) and reports the value in regis-

ter 0x03. This value is also used by the speaker limiter

circuitry to set accurate thresholds. When the battery

measurement function is disabled, the battery voltage is

user programmable.

Table 36. Battery Measurement Registers

0x03

VBAT

Battery Voltage

Read VBAT when VBATEN = 1 to determine VSPKLVDD. Program VBAT when VBATEN

= 0 to allow proper speaker amplifier signal processing. Calculate the battery voltage

using the following formula:

VBATTERY = 2.55V + [VBAT/10]

0x4C

7SHDN See the Power Management section.

6 VBATEN

Battery Measurement Enable

Enables an internal ADC to measure VSPKLVDD.

0 = Disabled (register 0x03 readable and writeable)

1 = Enabled (register 0x03 read only)

1 JDWK See the Headset Detection section.

Stereo Audio CODEC

with FlexSound Technology

MAX9888

103

Table 37. Status and Interrupt Registers

Device Status

The IC uses register 0x00 and IRQ to report the status of

various device functions. The status register bits are set

when their respective events occur, and cleared upon

reading the register. Device status can be determined

either by poling register 0x00 or configuring the IRQ to

pull low when specific events occur. IRQ is an open-

drain output that requires a pullup resistor for proper

operation. Register 0x0F determines which bits in the

status register trigger IRQ to pull low.

0x00

(Read Only)

7 CLD

Full Scale

0 = All digital signals are less than full scale.

1 = The DAC or ADC signal path has reached or exceeded full scale. This typically

indicates clipping.

6 SLD

Volume Slew Complete

SLD reports that any of the programmable-gain arrays or volume controllers has

completed slewing from a previous setting to a new programmed setting. If multiple

gain arrays or volume controllers are changed at the same time, the SLD flag is set

after the last volume slew completes. SLD also reports when the digital audio interface

soft-start or soft-stop process has completed. MCLK is required for proper SLD

operation.

0 = No volume slewing sequences have completed since the status register was last

read.

1 = Volume slewing complete.

5 ULK

Digital Audio Interface Unlocked

0 = Both digital audio interfaces are operating normally.

1 = Either digital audio interface is configured incorrectly or receiving invalid data.

1 JDET

Jack Configuration Change

JDET reports changes to any bit in the Jack Status register (0x02). Changes to the Jack

Status bits are debounced before setting JDET. The debounce period is programmable

using the JDEB bits. JDET is always set the first time JDETEN or SHDN is set the first

time power is applied to the IC. Read the status register following such an event to clear

JDET and allow for proper jack detection.

0 = No change in jack configuration.

1 = Jack configuration has changed.

0x0F

7 ICLD

Full-Scale Interrupt Enable

0 = Disabled

1 = Enabled

6 ISLD

Volume Slew Complete Interrupt Enable

0 = Disabled

1 = Enabled

5 IULK

Digital Audio Interface Unlocked Interrupt Enable

0 = Disabled

1 = Enabled

1 IJDET

Jack Configuration Change Interrupt Enable

0 = Disabled

1 = Enabled

Stereo Audio CODEC

with FlexSound Technology

MAX9888

104

Table 38. Device Revision Register

Figure 33. START, STOP, and REPEATED START Conditions

I2C Serial Interface

The IC features an I2C/SMBusK-compatible, 2-wire

serial interface comprising a serial-data line (SDA) and

a serial-clock line (SCL). SDA and SCL facilitate com-

munication between the IC and the master at clock rates

up to 400kHz. Figure 5 shows the 2-wire interface timing

diagram. The master generates SCL and initiates data

transfer on the bus. The master device writes data to the

IC by transmitting the proper slave address followed by

the register address and then the data word. Each trans-

mit sequence is framed by a START (S) or REPEATED

START (Sr) condition and a STOP (P) condition. Each

word transmitted to the IC is 8 bits long and is followed

by an acknowledge clock pulse. A master reading data

from the IC transmits the proper slave address followed

by a series of nine SCL pulses. The IC transmits data on

SDA in sync with the master-generated SCL pulses. The

master acknowledges receipt of each byte of data. Each

read sequence is framed by a START or REPEATED

START condition, a not acknowledge, and a STOP condi-

tion. SDA operates as both an input and an open-drain

output. A pullup resistor, typically greater than 500I,

is required on SDA. SCL operates only as an input. A

pullup resistor, typically greater than 500I, is required

on SCL if there are multiple masters on the bus, or if

the single master has an open-drain SCL output. Series

resistors in line with SDA and SCL are optional. Series

resistors protect the digital inputs of the IC from high

voltage spikes on the bus lines, and minimize crosstalk

and undershoot of the bus signals.

Bit Transfer

One data bit is transferred during each SCL cycle. The

data on SDA must remain stable during the high period of

the SCL pulse. Changes in SDA while SCL is high are con-

trol signals (see the START and STOP Conditions section).

START and STOP Conditions

SDA and SCL idle high when the bus is not in use. A

master initiates communication by issuing a START

condition. A START condition is a high-to-low transition

on SDA with SCL high. A STOP condition is a low-to-

high transition on SDA while SCL is high (Figure 33). A

START condition from the master signals the beginning

of a transmission to the IC. The master terminates trans-

mission, and frees the bus, by issuing a STOP condition.

The bus remains active if a REPEATED START condition

is generated instead of a STOP condition.

Early STOP Conditions

The IC recognizes a STOP condition at any point during

data transmission except if the STOP condition occurs in

the same high pulse as a START condition. For proper

operation, do not send a STOP condition during the

same SCL high pulse as the START condition.

SMBus is a trademark of Intel Corp.

Device Revision

0xFF

(Read Only)

REV Device Revision Code

REV is always set to 0x43.

SCL

SDA

S Sr P

Stereo Audio CODEC

with FlexSound Technology

MAX9888

105

Slave Address

The slave address is defined as the seven most signifi-

cant bits (MSBs) followed by the read/write bit. For the

IC, the seven most significant bits are 0010000. Setting

the read/write bit to 1 (slave address = 0x21) configures

the IC for read mode. Setting the read/write bit to 0 (slave

address = 0x20) configures the IC for write mode. The

address is the first byte of information sent to the IC after

the START condition.

Acknowledge

The acknowledge bit (ACK) is a clocked 9th bit that the

IC uses to handshake receipt each byte of data when

in write mode (Figure 34). The IC pulls down SDA dur-

ing the entire master-generated 9th clock pulse if the

previous byte is successfully received. Monitoring ACK

allows for detection of unsuccessful data transfers. An

unsuccessful data transfer occurs if a receiving device

is busy or if a system fault has occurred. In the event

of an unsuccessful data transfer, the bus master retries

communication. The master pulls down SDA during the

9th clock cycle to acknowledge receipt of data when

the IC is in read mode. An acknowledge is sent by the

master after each read byte to allow data transfer to

continue. A not acknowledge is sent when the master

reads the final byte of data from the IC, followed by a

STOP condition.

Write Data Format

A write to the IC includes transmission of a START condi-

tion, the slave address with the R/W bit set to 0, one byte

of data to configure the internal register address pointer,

one or more bytes of data, and a STOP condition. Figure

35 illustrates the proper frame format for writing one byte

of data to the IC. Figure 35 illustrates the frame format for

writing n-bytes of data to the IC.

Figure 34. Acknowledge

Figure 35. Writing One Byte of Data to the IC

Figure 36. Writing n-Bytes of Data to the IC

SCL

START

CONDITION

SDA

2 8 9

CLOCK PULSE FOR

ACKNOWLEDGMENT

ACKNOWLEDGE

NOT ACKNOWLEDGE

1 BYTE

AUTOINCREMENT INTERNAL REGISTER ADDRESS POINTER

ACKNOWLEDGE FROM MAX9888

B7 B6 B5 B4 B3 B2 B1 B0

ACKNOWLEDGE FROM MAX9888

SOAAA PSLAVE ADDRESS

R/W

ACKNOWLEDGE FROM MAX9888

SLAVE ADDRESS REGISTER ADDRESS DATA BYTE 1

AUTOINCREMENT INTERNAL REGISTER ADDRESS POINTER

1 BYTE

ACKNOWLEDGE FROM MAX9888

ACKNOWLEDGE FROM MAX9888 ACKNOWLEDGE FROM MAX9888

B7 B6 B5 B4 B3 B2 B1 B0 B7 B6 B5 B4 B3 B2 B1 B0

SOAAADATA BYTE n

1 BYTE

R/W

Stereo Audio CODEC

with FlexSound Technology

MAX9888

106

The slave address with the R/W bit set to 0 indicates

that the master intends to write data to the IC. The IC

acknowledges receipt of the address byte during the

master-generated 9th SCL pulse.

The second byte transmitted from the master configures

the IC’s internal register address pointer. The pointer

tells the IC where to write the next byte of data. An

acknowledge pulse is sent by the IC upon receipt of the

address pointer data.

The third byte sent to the IC contains the data that is

written to the chosen register. An acknowledge pulse

from the IC signals receipt of the data byte. The address

pointer autoincrements to the next register address after

each received data byte. This autoincrement feature

allows a master to write to sequential registers within

one continuous frame. The master signals the end of

transmission by issuing a STOP condition. Register

addresses greater than 0xC7 are reserved. Do not write

to these addresses.

Read Data Format

Send the slave address with the R/W bit set to 1 to initi-

ate a read operation. The IC acknowledges receipt of

its slave address by pulling SDA low during the 9th SCL

clock pulse. A START command followed by a read com-

mand resets the address pointer to register 0x00.

The first byte transmitted from the IC is the content of

edge of SCL. The address pointer autoincrements after

each read data byte. This autoincrement feature allows

all registers to be read sequentially within one continu-

ous frame. A STOP condition can be issued after any

number of read data bytes. If a STOP condition is issued

followed by another read operation, the first data byte to

be read is from register 0x00.

The address pointer can be preset to a specific register

before a read command is issued. The master presets

the address pointer by first sending the IC’s slave

address with the R/W bit set to 0 followed by the register

address. A REPEATED START condition is then sent fol-

lowed by the slave address with the R/W bit set to 1. The

IC then transmits the contents of the specified register.

The address pointer autoincrements after transmitting

the first byte.

The master acknowledges receipt of each read byte

during the acknowledge clock pulse. The master must

acknowledge all correctly received bytes except the last

byte. The final byte must be followed by a not acknowl-

edge from the master and then a STOP condition. Figure

37 illustrates the frame format for reading one byte from

the IC. Figure 38 illustrates the frame format for reading

multiple bytes from the IC.

Figure 37. Reading One Byte of Data from the IC

Figure 38. Reading n Bytes of Data from the IC

ACKNOWLEDGE FROM MAX9888 ACKNOWLEDGE FROM MAX9888 ACKNOWLEDGE FROM MAX9888 NOT ACKNOWLEDGE FROM MASTER

AUTOINCREMENT INTERNAL REGISTER ADDRESS POINTER

1 BYTE

REPEATED START

SO A ASr 1AA

SLAVE ADDRESS REGISTER ADDRESS SLAVE ADDRESS DATA BYTE

R/W

ACKNOWLEDGE FROM MAX9888 ACKNOWLEDGE FROM MAX9888 ACKNOWLEDGE FROM MAX9888

AUTOINCREMENT INTERNAL REGISTER ADDRESS POINTER

1 BYTE

REPEATED START

SOAA Sr 1 AA

SLAVE ADDRESS REGISTER ADDRESS SLAVE ADDRESS DATA BYTE

R/W R/W

Stereo Audio CODEC

with FlexSound Technology

MAX9888

107

Applications Information

Typical Operating Circuits

Figures 39 and 40 provide example operating circuits for

the IC. The external components shown are the minimum

required for the IC to operate. Additional components

may be required by the application.

Figure 39. Typical Application Circuit Using Analog Microphone Inputs and the Bypass Switch

Analog Microphones and Bypass Switch

2.2kI

1kI

IRQ

1.8V TO

5.5V

10kI

TO MICROCONTROLLER

10MHz TO 60MHz CLOCK INPUT

DIGITAL AUDIO

PORT 1

I2C CONTROL

PORT

MICROPHONE

OUTPUT TO

BASEBAND

JACKSNS

HEADSET

MICROPHONE 1FF

1FF

1FF 1FF 2.2FF

1FF

HANDSET

MICROPHONE 1FF

1FF

DIGITAL

AUDIO

PORT 2

JACKSNS

BYPASS

SWITCH

INPUT

LRCLKS2

BCLKS2

SDINS2

SDOUTS2

JACKSNS

RECP/RXINP

RECN/RXINN

SPKLP

SPKLN

SPKRP

SPKRN

HPR

HPL

HPSNS

REF

PREG

REG

MCLK

BCLKS1

LRCLKS1

SDINS1

SDOUTS1

SDA

SCL

MIC1P/DIGMICDATA

MIC1N/DIGMICCLK

MICBIAS

MIC2P

MIC2N

INA1/EXTMICP

INA2/EXTMICN

INB1

INB2

LINE INPUT 1FF

1FF

AGND HPGND SPKRGND SPKLGND C1NHPVSS C1PDGND

DVDDS1 DVDD HPVDD AVDD SPKLVDD SPKRVDD DVDDS2

1FF 1FF

10FF1.8V TO 3.6V

2.8V TO 5.5V

1.8V

1.8V TO 3.6V

1FF 1FF 1FF 1FF 1FF

MAX9888

Stereo Audio CODEC

with FlexSound Technology

MAX9888

108

Figure 40. Typical Application Circuit Using the Digital Microphone Input and Receiver Amplifier

Digital Microphones and Receiver Amplifier

IRQ

10kI

TO MICROCONTROLLER

10MHz TO 60MHz

CLOCK INPUT

DIGITAL AUDIO

PORT 1

I2C CONTROL

PORT

1FF 1FF 2.2FF

DIGITAL

AUDIO

PORT 2

JACKSNS

LRCLKS2

BCLKS2

SDINS2

SDOUTS2

JACKSNS

RECP/RXINP

RECN/RXINN

SPKLP

SPKLN

SPKRP

SPKRN

HPR

HPL

HPSNS

REF

PREG

REG

MCLK

BCLKS1

LRCLKS1

SDINS1

SDOUTS1

SDA

SCL

MIC1P/DIGMICDATA

MIC1N/ DIGMICCLK

MICBIAS

MIC2P

MIC2N

INA1/EXTMICP

INA2/EXTMICN

INB1

INB2

2.2kI

DIGITAL

MIC 1

DIGITAL

MIC 2

JACKSNS

HEADSET

MICROPHONE 1FF

1FF

DATA

CLOCK

DATA

CLOCK

1FF

AGND HPGND SPKRGND SPKLGND C1NHPVSS

C1P

DGND

LINE INPUT 1FF

1FF

LINE INPUT 1FF

1FF

32I

DVDDS1 DVDD HPVDD AVDD SPKLVDD SPKRVDD DVDDS2

1FF 1FF

10FF1.8V TO 3.6V

1.8V

1.8V TO 3.6V

1FF 1FF 1FF 1FF 1FF

2.8V TO 5.5V

1.8V TO

5.5V

MAX9888

Stereo Audio CODEC

with FlexSound Technology

MAX9888

109

Filterless Class D Operation

Traditional Class D amplifiers require an output filter

to recover the audio signal from the amplifier’s output.

The filters add cost, increase the solution size of the

amplifier, and can decrease efficiency and THD+N

performance. The traditional PWM scheme uses large

differential output swings (2 x VDD peak to peak) and

causes large ripple currents. Any parasitic resistance in

the filter components results in a loss of power, lowering

the efficiency.

The IC does not require an output filter. The device relies

on the inherent inductance of the speaker coil and the

natural filtering of both the speaker and the human ear

to recover the audio component of the square-wave out-

put. Eliminating the output filter results in a smaller, less

costly, more efficient solution.

Because the frequency of the IC output is well beyond

the bandwidth of most speakers, voice coil move-

ment due to the square-wave frequency is very small.

Although this movement is small, a speaker not designed

to handle the additional power can be damaged. For

optimum results, use a speaker with a series inductance

> 10FH. Typical 8I speakers exhibit series inductances

in the 20FH to 100FH range.

RF Susceptibility

GSM radios transmit using time-division multiple access

(TDMA) with 217Hz intervals. The result is an RF signal

with strong amplitude modulation at 217Hz and its har-

monics that is easily demodulated by audio amplifiers.

The IC is designed specifically to reject RF signals; how-

ever, PCB layout has a large impact on the susceptibility

of the end product.

In RF applications, improvements to both layout and com-

ponent selection decrease the IC’s susceptibility to RF

noise and prevent RF signals from being demodulated into

audible noise. Trace lengths should be kept below 1/4 of

the wavelength of the RF frequency of interest. Minimizing

the trace lengths prevents them from functioning as anten-

nas and coupling RF signals into the IC. The wavelength

(l) in meters is given by: l = c/f where c = 3 x 108 m/s, and

f = the RF frequency of interest.

Route audio signals on middle layers of the PCB to allow

ground planes above and below to shield them from RF

interference. Ideally, the top and bottom layers of the

PCB should primarily be ground planes to create effec-

tive shielding.

Additional RF immunity can also be obtained by rely-

ing on the self-resonant frequency of capacitors as it

exhibits a frequency response similar to a notch filter.

Depending on the manufacturer, 10pF to 20pF capaci-

tors typically exhibit self resonance at the RF frequencies

of interest. These capacitors, when placed at the input

pins, can effectively shunt the RF noise to ground. For

these capacitors to be effective, they must have a low-

impedance, low-inductance path to the ground plane.

Avoid using microvias to connect to the ground plane

whenever possible as these vias do not conduct well at

RF frequencies.

Startup/Shutdown Sequencing

To ensure proper device initialization and minimal click-

and-pop, program the IC’s SHDN = 1 after configuring all

registers. Table 39 lists an example startup sequence for

the device. To shut down the IC, simply set SHDN = 0.

Table 39. Example Startup Sequence

SEQUENCE DESCRIPTION REGISTERS

1 Ensure SHDN = 0 0x4C

2 Configure clocks 0x10 to 0x13, 0x19 to 0x1B

3 Configure digital audio interface 0x14 to 0x17, 0x1C to 0x1F

4 Configure digital signal processing 0x18, 0x20, 0x3D to 0x44

5 Load coefficients 0x50 to 0xC7

6 Configure mixers 0x21 to 0x29

7 Configure gain and volume controls 0x2A to 0x3C

8 Configure miscellaneous functions 0x45 to 0x49

9 Enable desired functions 0x4A, 0x4B

10 Set SHDN = 1 0x4C

Stereo Audio CODEC

with FlexSound Technology

MAX9888

110

While many configuration options in the IC can be made

while the device is operating, some registers should

only be adjusted when the corresponding audio path is

disabled. Table 40 lists the registers that are sensitive

during operation. Either disable the corresponding audio

path or set SHDN = 0 while changing these registers.

Component Selection

Optional Ferrite Bead Filter

In applications where speaker leads exceed 20mm,

additional EMI suppression can be achieved by using a

filter constructed from a ferrite bead and a capacitor to

ground (Figure 41). Use a ferrite bead with low DC resis-

tance, high-frequency (> 600MHz) impedance between

100I and 600I, and rated for at least 1A. The capacitor

value varies based on the ferrite bead chosen and the

actual speaker lead length. Select a capacitor less than

1nF based on EMI performance.

Input Capacitor

An input capacitor, CIN, in conjunction with the input

impedance of the IC line inputs forms a highpass filter

that removes the DC bias from an incoming analog

signal. The AC coupling capacitor allows the amplifier

to automatically bias the signal to an optimum DC level.

Assuming zero-source impedance, the -3dB point of the

highpass filter is given by:

-3dB IN IN

f2 R C

Choose CIN so that f-3dB is well below the lowest fre-

quency of interest. For best audio quality use capacitors

whose dielectrics have low-voltage coefficients, such as

tantalum or aluminum electrolytic. Capacitors with high-

voltage coefficients, such as ceramics, may result in

increased distortion at low frequencies.

Charge-Pump Capacitor Selection

Use capacitors with an ESR less than 100mI for optimum

performance. Low-ESR ceramic capacitors minimize the

output resistance of the charge pump. Most surface-

mount ceramic capacitors satisfy the ESR requirement.

For best performance over the extended temperature

range, select capacitors with an X7R dielectric.

Table 40. Registers That Are Sensitive to Changes During Operation

Figure 41. Optional Class D Ferrite Bead Filter

0x10 to 0x13, 0x19 to 0x1B Clock Control Registers

0x14 to 0x17, 0x1C to 0x1F Digital Audio Interface Configuration

0x18, 0x20 Digital Passband Filters

0x24 to 0x29 Analog Mixers

0x50 to 0xC7 Digital Signal Processing Coefficients

MAX9888

SPK_P

SPK_N

Stereo Audio CODEC

with FlexSound Technology

MAX9888

111

Charge-Pump Flying Capacitor

The value of the flying capacitor (connected between

C1N and C1P) affects the output resistance of the

charge pump. A value that is too small degrades the

device’s ability to provide sufficient current drive, which

leads to a loss of output voltage. Increasing the value

of the flying capacitor reduces the charge-pump output

resistance to an extent. Above 1FF, the on-resistance

of the internal switches and the ESR of external charge-

pump capacitors dominate.

Charge-Pump Holding Capacitor

The holding capacitor (bypassing HPVSS) value and

ESR directly affect the ripple at HPVSS. Increasing

the capacitor’s value reduces output ripple. Likewise,

decreasing the ESR reduces both ripple and output

resistance. Lower capacitance values can be used in

systems with low maximum output power levels. See the

Output Power vs. Load Resistance graph in the Typical

Operating Characteristics section for more information

Unused Pins

Table 41 shows how to connect the IC’s pins when

unused.

Table 41. Unused Pins

NAME CONNECTION NAME CONNECTION

SPKRP Unconnected INB1 Unconnected

SPKRVDD Always connected INA2/MICEXTN Unconnected

SPKLVDD Always connect LRCLKS2 Unconnected

SPKLP Unconnected MCLK Always connect

RECN/RXINN Unconnected SDINS2 AGND

HPVDD Always connect IRQ Unconnected

C1P Unconnected MIC1P/DIGMICDATA Unconnected

HPGND AGND INA1/MICEXTP Unconnected

SPKRN Unconnected DGND Always connect

SPKRGND Always connect BCLKS2 Unconnected

SPKLGND Always connect SDA Always connect

SPKLN Unconnected SCL Always connect

RECP/RXINP Unconnected REG Always connect

C1N Unconnected REF Always connect

HPL Unconnected MIC1N/DIGMICCLK Unconnected

HPVSS Unconnected MIC2P Unconnected

SDINS1 AGND SDOUTS2 Unconnected

LRCLKS1 Unconnected DVDDS2 DVDD

HPSNS AGND DVDD Always connect

INB2 Unconnected AVDD Always connect

HPR Unconnected PREG Always connect

DVDDS1 DVDD AGND Always connect

SDOUTS1 Unconnected MICBIAS Unconnected

BCLKS1 Unconnected MIC2N Unconnected

JACKSNS Unconnected

Stereo Audio CODEC

with FlexSound Technology

MAX9888

112

Recommended PCB Routing

The IC uses a 63-bump WLP package. Figure 42

provides an example of how to connect to all active

bumps using 3 layers of the PCB. To ensure uninter-

rupted ground returns, use layer 2 as a connecting layer

between layer 1 and layer 2 and flood the remaining area

with ground.

Supply Bypassing, Layout, and Grounding

Proper layout and grounding are essential for optimum

performance. When designing a PCB for the IC, parti-

tion the circuitry so that the analog sections of the IC are

separated from the digital sections. This ensures that the

analog audio traces are not routed near digital traces.

Use a large continuous ground plane on a dedicated

layer of the PCB to minimize loop areas. Connect AGND,

DGND, HPGND, SPKLGND, and SPKRGND directly to

the ground plane using the shortest trace length pos-

sible. Proper grounding improves audio performance,

minimizes crosstalk between channels, and prevents

any digital noise from coupling into the analog audio

signals.

Ground the bypass capacitors on MICBIAS, REG, PREG,

and REF directly to the ground plane with minimum

trace length. Also be sure to minimize the path length to

AGND. Bypass AVDD directly to AGND.

Connect all digital I/O termination to the ground plane

with minimum path length to DGND. Bypass DVDD,

DVDDS1, and DVDDS2 directly to DGND.

Place the capacitor between C1P and C1N as close as

possible to the IC to minimize trace length from C1P to

C1N. Inductance and resistance added between C1P

and C1N reduce the output power of the headphone

amplifier. Bypass HPVSS with a capacitor located close

to HPVSS with a short trace length to HPGND. Close

decoupling of HPVSS minimizes supply ripple and maxi-

mizes output power from the headphone amplifier.

HPSNS senses ground noise on the headphone jack and

adds the same noise to the output audio signal, thereby

making the output (headphone output minus ground)

noise free. Connect HPSNS to the headphone jack shield

to ensure accurate pickup of headphone ground noise.

Bypass SPKLVDD and SPKRVDD to SPKLGND and

SPKRGND, respectively, with as little trace length as

possible. Connect SPKLP, SPKLN, SPKRP, and SPKRN

to the stereo speakers using the shortest traces pos-

sible. Reducing trace length minimizes radiated EMI.

Route SPKLP/SPKLN and SPKRP/SPKRN as differential

pairs on the PCB to minimize loop area, thereby the

inductance of the circuit. If filter components are used

on the speaker outputs, be sure to locate them as close

as possible to the IC to ensure maximum effectiveness.

Minimize the trace length from any ground-connected

passive components to SPKLGND and SPKRGND to

further minimize radiated EMI.

Figure 42. Suggested Routing

LAYER 1

LAYER 2

LAYER 3

Stereo Audio CODEC

with FlexSound Technology

MAX9888

113

Route microphone signals from the microphone to the IC

as a differential pair, ensuring that the positive and nega-

tive signals follow the same path as closely as possible

with equal trace length. When using single-ended micro-

phones or other single-ended audio sources, ground the

negative microphone input as close as possible to the

audio source and then treat the positive and negative

traces as differential pairs.

An evaluation kit (EV kit) is available to provide an exam-

ple layout for the IC. The EV kit allows quick setup of the

IC and includes easy-to-use software allowing all internal

registers to be controlled.

WLP Applications Information

For the latest application details on WLP construction,

dimensions, tape carrier information, PCB techniques,

bump-pad layout, and recommended reflow tempera-

ture profile, as well as the latest information on reliability

testing results, refer to the Application Note 1891: Wafer-

Level Packaging (WLP) and Its Applications. Figure 43

shows the dimensions of the WLP balls used on the IC. Figure 43. WLP Ball Dimensions

0.24mm

0.21mm

Stereo Audio CODEC

with FlexSound Technology

MAX9888

114

Package Information

For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the

package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the

package regardless of RoHS status.

PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.

63 WLP W633A3+1 21-0462 Refer to

Application Note 1891

Stereo Audio CODEC

with FlexSound Technology

MAX9888

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.

Maxim reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 115

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 6/10 Initial release —

1 2/11 Updated DAC playback 48kHz stereo, speaker outputs, speaker maximum value 6