_______________________________________________________________ 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.
MAX98400A Evaluation Kit
Evaluates: MAX98400A
General Description
The MAX98400A evaluation kit (EV kit) configures the
MAX98400A Class D amplifier to drive 2x20W into a pair of
8I speakers in stereo mode, or 1x40W into a 4I speaker
in mono mode, for audio applications. The EV kit operates
from an 8V to 28V DC power supply. The EV kit is config-
ured for +20.1dB gain. The EV kit accepts a pair of single-
ended or differential input signals and provides two sets of
differential outputs for speakers.
The EV kit has two independent MAX98400A circuits,
demonstrating direct speaker driving (for low component
count) and filtered output driving (for ease of evaluation).
The EV kit comes with two MAX98400AETX+ devices
installed.
The EV kit provides an option to control the limiter,
thermal foldback, input configuration, gain, shutdown,
and mono mode of the MAX98400A. The EV kit also
provides an input pad to accept an optional external power
supply for powering the device’s preamplifiers. The EV kit
includes convenient audio input and output connectors.
Features
S 8V to 28V Single DC Power-Supply Operation
S Fully Differential Inputs and Outputs
S Drives 2x20W into 8I Speakers in Stereo Mode
S Drives 1x40W into 4I Speaker in Mono Mode
S Limiter Control
S Thermal Foldback
S Shutdown Control
S Evaluates the MAX98400A in a 36-Pin TQFN
Package with an Exposed Pad
S U1 Configured for Filterless Output
S U2 Configured for Filtered Output
S Fully Assembled and Tested
Ordering Information
19-5477; Rev 0; 8/10
+Denotes lead(Pb)-free and RoHS compliant.
Component List
PART TYPE
MAX98400AEVKIT+ EV Kit
DESIGNATION QTY DESCRIPTION
FILTERLESS EVALUATION (U1)
C101 1
220FF Q20%, 35V electrolytic
capacitor (radial leaded, 5mm
spacing), 10mm diameter x
12.5mm high
Panasonic EEU-FM1V221
C102A, C102B 2
1FF Q10%, 50V X7R ceramic
capacitors (0805)
TDK C2012X7R1H105K
C103, C104 2
1FF Q10%, 10V X7R ceramic
capacitors (0603)
Murata GRM188R71A105K
C105–C108 4
1FF Q10%, 25V X7R ceramic
capacitors (0805)
Murata GRM21BR71E105K
C111–C114 0 Not installed, ceramic
capacitors (0603)
FB1 1
22I at 100MHz ferrite bead
(0805)
Murata BLM21PG220SN1D
DESIGNATION QTY DESCRIPTION
GAIN1_1,
GAIN2_1, LIM_1 3 3-pin headers
INL1 1 White phono jack
INR1 1 Red phono jack
JU104, JU105,
SHDN_1, TEMP_1 4 2-pin headers
L1+, L1-, R1+,
R1- 0Not installed, multipurpose test
points
MONO_1 0 Not installed, 2-pin header
R101, R103,
R104, R105 0 Not installed, resistors (0603)
R102, R107 2 100kI Q5% resistors (0603)
R106 0 Not installed, potentiometer
(3/8in)
R111–R114 4 0I Q5% resistors
SPKL1+, SPKL1-,
SPKR1+, SPRK1- 4 Binding posts
MAX98400A Evaluation Kit
Evaluates: MAX98400A
2 ______________________________________________________________________________________
*EP = Exposed pad.
Component List (continued)
DESIGNATION QTY DESCRIPTION
U1 1
Stereo Class D audio amplifier
(36 TQFN-EP*)
Maxim MAX98400AETX+
— 10
600I at 100MHz, 150mI DCR,
2A ferrite beads (0805)
Würth Elektronik 742792040
— 10
330pF Q10%, 50V X7R
ceramic capacitors (0603)
TDK C1608X7R1H331K
FILTERED EVALUATION (U2)
C201 1
220FF Q20%, 35V electrolytic
capacitor (radial leaded, 5mm
spacing), 10mm diameter x
12.5mm high
Panasonic EEU-FM1V221
C202A, C202B 2
1FF Q10%, 50V X7R ceramic
capacitors (0805)
TDK C2012X7R1H105K
C203, C204 2
1FF Q10%, 10V X7R ceramic
capacitors (0603)
Murata GRM188R71A105K
C205–C208 4
1FF Q10%, 25V X7R
ceramic capacitors (0805)
Murata GRM21BR71E105K
C220–C223,
C226–C229 8
0.15FF Q10%, 50V X7R
ceramic capacitors (0805)
Murata GRM21BR71H154K
C224, C225 2
0.68FF Q10%, 50V X7R
ceramic capacitors (1206)
Murata GRM31MR71H684K
FB2 1 22I ferrite bead (0805)
Murata BLM21PG220SN1D
FOUTL2+,
FOUTL2-,
FOUTR2+,
FOUTR2-
4 Binding posts
DESIGNATION QTY DESCRIPTION
GAIN1_2,
GAIN2_2, LIM_2 3 3-pin headers
INL2 1 White phono jack
INR2 1 Red phono jack
JU204, JU205,
SHDN_2, TEMP_2 4 2-pin headers
L20–L23 4
33FH Q20%, 3.0A inductors
(12.3mm x 12.3mm)
Sumida CDRH127NP-330NC
MONO_2 0 Not installed, 2-pin header
R201, R203,
R204, R205 0 Not installed, resistors (0603)
R202, R207 2 100kI Q5% resistors (0603)
R206 0 Not installed, potentiometer
(3/8in)
R226–R229 4 15I Q5% resistors (1206)
U2 1
Stereo Class D audio amplifier
(36 TQFN-EP*)
Maxim MAX98400AETX+
COMMON TO BOTH SIDES
C1 1
0.1FF Q10%, 50V X7R ceramic
capacitor (0603)
Murata GRM188R71H104K
C2 1
1FF Q10%, 10V X7R ceramic
capacitor (0603)
Murata GRM188R71A105K
D1 1
4.3V, 20mA zener diode
(SOT23)
Central Semi CMPZ5229B
JU1 1 3-pin header
PGND, PVDD 2 Binding posts
R1 1 10kI Q5% resistor (0603)
— 13 Shunts
— 1 PCB: MAX98400A
EVALUATION KIT+
MAX98400A Evaluation Kit
Evaluates: MAX98400A
_______________________________________________________________________________________ 3
Quick Start
Required Equipment
• MAX98400A EV kit
• 8V to 28V, 5A DC power supply
• Audio source with volume control (e.g., CD player)
• Two speakers
Procedure—Filterless Evaluation (U1)
The EV kit is fully assembled and tested. Follow the
steps below to verify board operation. Caution: Do not
turn on the power supply until all connections are
completed.
1) Verify that all jumpers are in their default positions,
as shown in Table 1.
2) If not using the filtered evaluation side, remove the
shunt on SHDN_2 (disable).
3) Connect the first speaker across the SPKL1- and
SPKL1+ PCB binding posts.
4) Connect the second speaker across the SPKR1-
and SPKR1+ PCB binding posts.
5) Connect the positive terminal of the power supply
to the PVDD binding post and the power-supply
ground terminal to the PGND binding post.
6) Connect the left output terminal of the audio source
to the INL1 RCA phono jack.
7) Connect the right output terminal of the audio
source to the INR1 RCA phono jack.
8) Turn on the audio source at minimum volume.
9) Turn on the power supply.
10) Gradually increase the audio source volume until
audio is heard through the loud speakers.
Procedure—Filtered Evaluation (U2)
The EV kit is fully assembled and tested. Follow the
steps below to verify board operation. Caution: Do not
turn on the power supply until all connections are
completed.
1) Verify that all jumpers are in their default positions,
as shown in Table 2.
2) If not using the filterless evaluation side, remove the
shunt on SHDN_1 (disable).
3) Connect the first speaker across the FOUTL2- and
FOUTL2+ PCB binding posts.
4) Connect the second speaker across the FOUTR2-
and FOUTR2+ PCB binding posts.
5) Connect the positive terminal of the power supply
to the PVDD binding post and the power-supply
ground terminal to the PGND binding post.
6) Connect the left output terminal of the audio source
to the INL2 RCA phono jack.
7) Connect the right output terminal of the audio
source to the INR2 RCA phono jack.
8) Turn on the audio source at minimum volume.
9) Turn on the power supply.
10) Gradually increase the audio source volume until
audio is heard through the loud speakers.
Component Suppliers
Note: Indicate that you are using the MAX98400A when contacting these component suppliers.
SUPPLIER PHONE WEBSITE
Central Semiconductor Corp. 631-435-1110 www.centralsemi.com
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
Panasonic Corp. 800-344-2112 www.panasonic.com
Sumida Corp. 847-545-6700 www.sumida.com
TDK Corp. 847-803-6100 www.component.tdk.com
Würth Electronik GmbH & Co. KG 201-785-8800 www.we-online.com
MAX98400A Evaluation Kit
Evaluates: MAX98400A
4 ______________________________________________________________________________________
Detailed Description of Hardware
The MAX98400A EV kit provides a proven layout for eval-
uating the MAX98400A. The EV kit is designed to evaluate
the device in a 36-pin TQFN package with an exposed
pad. The device is a Class D amplifier that can be config-
ured to drive 2x20W into a pair of 8Ω speakers, or 1x40W
into a 4Ω speaker. The EV kit operates from a DC power
supply that provides 8V to 28V and 5A of current. The EV
kit PCB is designed with two layers and has 2oz copper
for optimized power dissipation. Each side of the EV
kit accepts a pair of differential or single-ended input
signals and provides two sets of amplified differential
audio outputs.
Optional External Preamplifier
Power Supply (VS)
The EV kit provides input pads (VS1 for U1 and VS2 for
U2) to accept an optional 5V external power supply for
powering the device’s preamplifiers when the internal
regulator is disabled. The external power supply for the
preamplifiers must be in the 4.5V to 5.5V range.
Filterless Output (U1)
The EV kit’s filterless outputs (SPKL1+/SPKL1- and
SPKR1+/SPKR1-) can be connected directly to a pair of
speaker loads without any filtering.
Output Filtering Requirements (U1)
The device can pass CE EN55022B regulations with only
ferrite-bead filters, especially when speaker-wire lengths
are less than or equal to 1m. To install the ferrite-bead
filters, first remove the 0Ω resistors (R111–R114). Next,
replace resistors R111–R114 with ferrite beads listed
in Table 3 (provided with the EV kit), and install filter
capacitors on the C111–C114 pads. The speaker wire
should be connected to the L1+/L1- and R1+/R1- test
points. Although component selection for the output filter
is dependent on speaker-wire length, the components in
Table 3 are provided with the EV kit as a starting point.
Final component selection should be determined during
EMC testing. Contact the factory, if required. Note that
an inductive load is required at this terminal. If using an
8Ω power resistor, add a 68µH series inductor. If using a
4Ω power resistor, add a 33µH series inductor.
Filtered Output (U2)
Audio analyzers typically cannot accept pulse-width
modulated (PWM) signals at their inputs. Therefore,
the EV kit features a pair of lowpass filters at each of
the outputs to ease evaluation. Use the filtering output
posts (FOUTL2+/FOUTL2- and FOUTR2+/FOUTR2-) to
connect the filtered PWM outputs to the audio analyzer.
The default lowpass filters at the EV kit outputs are opti-
mized for a pair of 8Ω power resistors or 8Ω speakers.
Mono Mode (MONO)
The EV kit is preconfigured for stereo mode at the facto-
ry. To change the EV kit to operate in mono mode, short
jumper MONO_1 (U1) or MONO_2 (U2) with a shorting
wire, connect SPKL1- to SPKR1- (U1) or FOUTL2- to
FOUTR2- (U2) with a short banana-lead cable, and
connect SPKL1+ to SPKR1+ (U1) or FOUTL2+ to
FOUTR+2 (U2) with a short banana-lead cable. Connect
the audio input source to the INL1 or INL2 RCA jack.
Thermal Foldback
As shipped from the factory, the thermal-foldback
feature is enabled (TEMP_1 and TEMP_2 jumpers open).
To disable thermal foldback, install a shunt across the
TEMP_1 and TEMP_2 jumpers. Refer to the MAX98400A/
MAX98400B IC data sheet.
Limiter
As shipped from the factory, the limiter-threshold control
is disabled. To enable the limiter in PVDD tracking mode,
move the LIM_1 or LIM_2 shunt to the 2-3 position. To
enable the limiter in programmable mode, leave the
LIM_1 or LIM_2 jumper open and select appropriate val-
ues for R103, R104, and R105 or R203, R204, and R205.
Refer to the MAX98400A/MAX98400B IC data sheet for
information on selecting these component values.
MAX98400A Evaluation Kit
Evaluates: MAX98400A
_______________________________________________________________________________________ 5
*Default position. *Default position.
Table 1. Jumper Descriptions (U1) Table 2. Jumper Descriptions (U2)
JUMPER SHUNT
POSITION DESCRIPTION
SHDN_1 1-2* Normal operation; U1 SHDN =
DVDD (external logic-high)
Open Shutdown; U1 SHDN = GND
TEMP_1
Open* Thermal foldback enabled; U1
TEMPLOCK = unconnected
1-2 Thermal foldback disabled; U1
TEMPLOCK = GND
MONO_1
Open* Stereo mode; U1 MONO is
pulled to GND by R102
1-2 Mono mode; U1 MONO is pulled
to VS1
LIM_1
1-2* Limiter disabled; U1 LIM_TH =
VS1
2-3 Limiter enabled in PVDD tracking
mode; U1 LIM_TH = GND
Open
Limiter programmable mode; U1
LIM_TH is determined by R103,
R104, and R105
JU104
1-2* Single-ended input mode; U1
INL- = GND
Open Differential input mode; U1 INL-
is not connected to GND
JU105
1-2* Single-ended input mode; U1
INR- = GND
Open Differential input mode; U1 INR-
is not connected to GND
GAIN1_1
1-2 U1 G1 = VS1
2-3* U1 G1 = GND
Open U1 G1 is not driven
GAIN2_1
1-2 U1 G2 = VS1
2-3 U1 G2 = GND
Open* U1 G2 is not driven
JUMPER SHUNT
POSITION DESCRIPTION
SHDN_2 1-2* Normal operation; U2 SHDN =
DVDD (external logic-high)
Open Shutdown; U2 SHDN = GND
TEMP_2
Open* Thermal foldback enabled; U2
TEMPLOCK = unconnected
1-2 Thermal foldback disabled; U2
TEMPLOCK = GND
MONO_2
Open* Stereo mode; U2 MONO is pulled
to GND by R202
1-2 Mono mode; U2 MONO is pulled
to VS2
LIM_2
1-2* Limiter disabled; U2 LIM_TH =
VS2
2-3 Limiter enabled in PVDD track-
ing; U2 LIM_TH = GND
Open
Limiter programmable mode; U2
LIM_TH is determined by R203,
R204, and R205
JU204
1-2* Single-ended input mode; U2
INL- = GND
Open Differential input mode; U2 INL-
is not connected to GND
JU205
1-2* Single-ended input mode; U2
INR- = GND
Open Differential input mode; U2 INR-
is not connected to GND
GAIN1_2
1-2 U2 G1 = VS2
2-3* U2 G1 = GND
Open U2 G1 is not driven
GAIN2_2
1-2 U2 G2 = VS2
2-3 U2 G2 = GND
Open* U2 G2 is not driven
MAX98400A Evaluation Kit
Evaluates: MAX98400A
6 ______________________________________________________________________________________
Figure 1a. MAX98400A EV Kit Schematic (Sheet 1 of 3)
Table 3. Recommended EMI Filter
Components for 8I Loads
Note: 3A current-rating ferrite beads are recommended for 4
I
load drive.
*GAIN1_1 and GAIN2_1 set the gain for U1.
GAIN1_2 and GAIN2_2 set the gain for U2.
Table 4. Gain Jumper Descriptions*
PVDD
PVDD
PGND
PGND
BINDING_POST
PVDD
BINDING_POST
PGND
C1
0.1uF C2
1uF
FB1
FERRITE
1
2
3
JU1 R1
10k
3
1
D1
4.3V , 20mA
FB2
FERRITE
DDVD1DDVP PVDD1
PVDD2
DESIGNATION DESCRIPTION
R111–R114
600I at 100MHz, 150mI DCR,
2A ferrite beads (0805)
Würth Elektronik 742792040
C111–C114
330pF Q10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H331K or
TDK C1608X7R1H331K
SHUNT POSITION GAIN (dB)
GAIN1_1, GAIN1_2 GAIN2_1, GAIN2_2
2-3
2-3
9.0
Open 13.0
1-2 16.7
2-3
Open
20.1
Open 23.3
1-2 26.4
2-3
1-2
29.8
Open 32.9
1-2 Reserved
MAX98400A Evaluation Kit
Evaluates: MAX98400A
_______________________________________________________________________________________ 7
Figure 1b. MAX98400A EV Kit Schematic (Sheet 2 of 3)
EP
TEMP_1
INL1+
INL1-
PGND
PGND
AGND
VS1
1
2
INL1
JU104
C105 1uF
C106 1uF
INR1+
INR1-
1
2
INR1
JU105
C107 1uF
C108 1uF
1
2
3
GAIN1_1
1
2
3
GAIN2_1
MONO_1
OPEN
R102
100k
C103
1uF
C104 1uF
SHDN_1
R101
OPEN
C111
OPEN
R111 0
C112
OPEN
R112 0
C113
OPEN
R113 0
C114
OPEN
R114 0
SPKL1+
BINDING_POST
SPKL1-
BINDING_POST
SPKR1-
BINDING_POST
SPKR1+
BINDING_POST
R103
OPEN
R104
OPEN
R105
OPEN
1
2
3
LIM_1
11 INL+
12 INL-
17 INR+
16 INR-
13 MONO
19
TEMPLOCK
4
OUTL+
5
OUTL+
1
OUTL-
2
OUTL-
24
OUTR+
23
OUTR+
26
OUTR-
27
OUTR-
10
LIM_TH
20
RELEASE
21
SHDN
7
N.C.
6
VS
33
PVDD
32
PVDD
31
PVDD
34 PGND
30 PGND
29 PGND
28 N.C.
15 GND
35 PGND
36 N.C.
3N.C.
8G1
9G2
14 GND
18 N.C.
22 N.C.
25 N.C.
U1
MAX98400A
+
C101
220uF
35V
L1+
L1-
R1+
R1-
C102A
1uF
3
1
2
R106
OPEN
C102B
1uF
R107
100k
VS1
PVDD1
VS1
DVDD
VS1
PVDD1 VS1
VS1
VS1
VS1
MAX98400A Evaluation Kit
Evaluates: MAX98400A
8 ______________________________________________________________________________________
Figure 1c. MAX98400A EV Kit Schematic (Sheet 3 of 3)
EP
INL2+
INL2-
PGND
PGND
AGND
VS2
1
2
INL2
1
2
JU204
C205 1uF
C206 1uF
INR2+
INR2-
1
2
INR2
1
2
JU205
C207 1uF
C208 1uF
1
2
3
GAIN1_2
1
2
3
GAIN2_2
MONO_2
OPEN
R202
100k
C203
1uF
C204
1uF
SHDN_2
R201
OPEN
TEMP_2
C226
0.15uF
C227
0.15uF
C228
0.15uF
C229
0.15uF
FOUTL2+
BINDING_POST
FOUTL2-
BINDING_POST
FOUTR2-
BINDING_POST
FOUTR2+
BINDING_POST
R203
OPEN
R204
OPEN
R205
OPEN
1
2
3
LIM_2
L20
33uH
L21
33uH
L22
33uH
L23
33uH
C220
0.15uF
C221
0.15uF
C222
0.15uF
C223
0.15uF
C224
0.68uF
C225
0.68uF
11 INL+
12 INL-
17 INR+
16 INR-
13 MONO
19
TEMPLOCK
4
OUTL+
5
OUTL+
1
OUTL-
2
OUTL-
24
OUTR+
23
OUTR+
26
OUTR-
27
OUTR-
10
LIM_TH
20
RELEASE
21
SHDN
7
N.C.
6
VS
33
PVDD
32
PVDD
31
PVDD
34 PGND
30 PGND
29 PGND
28 N.C.
15 GND
35 PGND
36 N.C.
3N.C.
8G1
9G2
14 GND
18 N.C.
22 N.C.
25 N.C.
U2
MAX98400A
R226
15
R227
15
R228
15
R229
15
+
C201
220uF
35V
31
2
R206
OPEN
C202A
1uF
C202B
1uF
R207
100k
VS2
PVDD2
DVDD
PVDD2
VS2
VS2
VS2
VS2
VS2
VS2
MAX98400A Evaluation Kit
Evaluates: MAX98400A
_______________________________________________________________________________________ 9
Figure 2. MAX98400A EV Kit Component Placement Guide—Component Side
1.0’’
MAX98400A Evaluation Kit
Evaluates: MAX98400A
10 _____________________________________________________________________________________
Figure 3. MAX98400A EV Kit PCB Layout—Component Side
1.0’’
MAX98400A Evaluation Kit
Evaluates: MAX98400A
______________________________________________________________________________________ 11
Figure 4. MAX98400A EV Kit PCB Layout—Solder Side
1.0’’
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.
12 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX98400A Evaluation Kit
Evaluates: MAX98400A
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 8/10 Initial release —
