ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 1 -
GENERAL DESCRIPTION
The AK5385B is a 24bit, 192kHz sampling 2ch A/D converter for high-end audio system. The modulator in
the AK5385B uses the Enhanced Dual Bit architecture and the AK5385B realizes high accuracy and low
cost. The AK5385B performs 114d B dynamic range, so the devic e is suitable for AV-amp, AV recorder
and musical instruments. The AK5385B is available in 28pin VSOP and SOP package, utilizing less board
space.
FEATURES
Sampling Rate: 8kHz ~ 216kHz
Full Differential Inputs
S/(N+D): 103dB
DR: 114dB
S/N: 114dB
High Performance Linear Phase Digital Anti-Alias filter
• Passband: 0~21.76 8kHz (@fs=48kHz)
• Ripple: 0.005dB
• Stopband: 100dB
Digital HPF
Power Supply: 5V ± 5%(Analog), 3.0 ~ 5.25V(Digital)
Power Dissipation: 183mW (@fs=48kHz)
Package: 28pin SOP / 28pin VSOP
AK5383/AK5393/AK5394A Semi-P in compatible
TEST
Decimation
Filter
Delta-Sigma
Modulator Decimation
Filter HPF
HPF
Audio I/F
Controller
DVDDAVDD DVSSAVSS
VREFR
VREFL
LIN+
LIN- Delta-Sigma
Modulator
RIN+
RIN-
DIF
PDN
LRCK
BICK
MCLK
SDTO
HPFE
M/S DFS1 DFS0 CKS1 CKS0VCOM
BVSS
OVF
Block diagram
24Bit 192kHz ∆Σ ADC
AK5385B
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 2 -
Ordering Guide
AK5385BVS –10 ~ +70°C 28pin SOP (1.27mm pitch)
AK5385BVF –40 ~ +85°C 28pin VSOP (0.65mm pitch)
AKD5385B Evaluation Board for AK5385B
Pin Layout
VCOM
LIN+
DVDD
DVSS
VREFL
AVSS
LIN-
CKS0
PDN
DIF
M/S
LRCK
BICK
OVF
Top View
8
7
6
5
4
3
2
1
21
22
23
24
25
26
27
28
TEST
RIN+
AVSS
AVDD
RIN-
AVSS
VREFR
9
10
11
12
13
14
18
19
20 HPFE
15
16
17
SDTO
CKS1
MCLK
DFS1
BVSS
DFS0
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 3 -
Compatibility with AK5383/AK5394A
AK5385B AK5383 AK5394A
Pin 1 VREFL VREFL VREFL+
Pin 2 AVSS GNDL VREFL−
Pin 3 VCOM VCOML VCOML
Pin 6 CKS0 ZCAL ZCAL
Pin 9 OVF CAL CAL
Pin 11 DIF SMODE2 SMODE2
Pin 12 M/S SMODE1 SMODE1
Pin 16 CKS1 FSYNC FSYNC
Pin 18 DFS0 DFS DFS0
Pin 20 DFS1 TEST DFS1
Pin 26 TEST VCOMR VCOMR
Pin 27 AVSS GNDR VREFR−
Pin 28 VREFR VREFR VREFR+
fs 8kHz ∼ 216kHz 1kHz ∼ 108kHz 1kHz ∼ 216kHz
MCLK at 48kHz 256/384/512fs 256fs 256fs
MCLK at 96kHz 256fs 128fs 128fs
MCLK at 192kHz 128fs Not Available 64fs
DR, S/N 114dB 110dB 123dB
Input Voltage ±2.9Vpp ±2.45Vpp ±2.4Vpp
Offset Calibra tion Not Available Available Available
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 4 -
Compare PCB layout example between AK5385B and AK5383
3.0 ~ 5.25V
Digital
VREFL
GNDL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
VCOML
AINL+
AINL-
ZCAL
VD
DGND
CAL
RSTN
SMODE2
SMODE1
LRCK
SCLK
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VREFR
GNDR
VCOMR
AINR+
AINR-
VA
AGND
BGND
TEST
HPFE
DFS
MCLK
FSYNC
SDATA
0.1µ
10µ
0.22µ
0.1µ
10µ
0.1µ
10µ
5V
Analog
Analog Ground 0.1µ10µ
0.22µ
3.0 ~ 5.25V
Digital
VREFL
AVSS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
VCOM
LIN+
LIN-
CKS0
DVDD
DVSS
OVF
PDN
DIF
M/S
LRCK
BICK
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VREFR
AVSS
TEST
RIN+
RIN-
AVDD
AVSS
BVSS
DFS1
HPFE
DFS0
MCLK
CKS1
SDTO
10µ
0.22µ
0.1µ
10µ
0.1µ
10µ
5V
Analog
10µ
AK5385BAK5383
0.1µ
Analog Ground
0.1µ
Pin # AK5383 AK5385B
VREFL VREFL
1 Lch Voltage Reference Output Pin, 3.75V
Normally, connected to GNDL with a 10µF
electrolytic capacitor and a 0.1µF ceramic capacitor.
Lch Voltage Reference Input Pin, AVDD
Normally, conne cted to AVSS with a 10µF
electrolytic capacit or and a 0.1µF ceramic capacitor.
ZCAL CKS0
6 Zero Calibra tion Control Pin
This pin controls the calibration reference signal. Master Clock Select 0 Pin
(Internal Pull-down Pi n, typ. 100kΩ)
CAL OVF
9 Calibration Active Signal Pin Analog Input Overflow Detect Pin
SMODE2 DIF
11 Serial Interface Mode Select Pin Audio Interface Format Pin
SMODE1 M/S
12 Serial Interface Mode Select Pin Master / Slave Mode Pin
FSYNC CKS1
16 Frame Synchronization Signal Pin
Master Clock Select 1 Pin
(Internal Pull-down Pi n, typ.100kΩ)
DFS DFS0
18 Double Speed Sam pling Mode Pin Sampli ng Speed Select 0 Pin
TEST DFS1
20 Test Pin (Internal Pull-down Pin) Sampli ng Speed Select 1 Pin
VCOMR TEST
26 Rch Common Voltage Pin, 2.75V Test Pin (Internal Pull-down Pin, typ. 100kΩ)
VREFR VREFR
28 Rch Voltage Reference Output Pin, 3.75V
Normally, connected to GNDL with a 10µF
electrolytic capacitor and a 0.1µF ceramic capacitor.
Rch Voltage Reference Input Pin, AVDD
Normally, conne cted to AVSS with a 10µF
electrolytic capacit or and a 0.1µF ceramic capacitor.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 5 -
Compare PCB layout example between AK5385B and AK5394 A
3.0 ~ 5.25V
Digital
VREFL+
VREFL-
1
2
3
4
5
6
7
8
9
10
11
12
13
14
VCOML
AINL+
AINL-
ZCAL
VD
DGND
CAL
RSTN
SMODE2
SMODE1
LRCK
SCLK
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VREFR+
VREFR-
VCOMR
AINR+
AINR-
VA
AGND
BGND
DFS1
HPFE
DFS0
MCLK
FSYNC
SDATA
0.1µ
10µ
0.22µ
0.1µ
10µ
0.1µ
10µ
5V
Analog
Analog Ground 0.1µ10µ
0.22µ
AK5394A
10µ10µ
3.0 ~ 5.25V
Digital
VREFL
AVSS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
VCOM
LIN+
LIN-
CKS0
DVDD
DVSS
OVF
PDN
DIF
M/S
LRCK
BICK
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VREFR
AVSS
TEST
RIN+
RIN-
AVDD
AVSS
BVSS
DFS1
HPFE
DFS0
MCLK
CKS1
SDTO
0.1µ
10µ
0.22µ
0.1µ
10µ
0.1µ
10µ
5V
Analog
0.1µ10µ
AK5385B
(short) (short)
Analog Ground
Pin # AK5394A AK5385B
VREFL+ VREFL
1 Lch Positive Voltage Reference Output Pin, 3.75V
Normally connected to AGND with a large
electrolytic capacitor and connected to VREFL−
with a 0.22µF ceramic capacitor.
Lch Voltage Reference Input Pin, AVDD
Normally, conne cted to AVSS with a 10µF
electrolytic capacit or and a 0.1µF ceramic capacitor.
VREFL− AVSS
2 Lch Negative Voltage Reference Output Pin, 1.25V
Normally connected to AGND with a large
electrolytic capacitor and connected to VREFL+
with a 0.22µF ceramic capacitor.
Analog Ground Pin
ZCAL CKS0
6 Zero Calibra tion Control Pin
This pin controls the calibration reference signal. Master Clock Select 0 Pin
(Internal Pull-down Pi n, typ. 100kΩ)
CAL OVF
9 Calibration Active Signal Pin Analog Input Overflow Detect Pin
SMODE2 DIF
11 Serial Interface Mode Select Pin Audio Interface Format Pin
SMODE1 M/S
12 Serial Interface Mode Select Pin Master / Slave Mode Pin
FSYNC CKS1
16 Frame Synchronization Signal Pin
Master Clock Select 1 Pin
(Internal Pull-down Pi n, typ. 100kΩ)
VREFR− AVSS
27 Rch Negative Voltage Reference Output Pin, 1.25V
Normally connected to AGND with a large
electrolytic capacitor and connected to VREFR+
with a 0.22µF ceramic capacitor.
Analog Ground Pin
VCOMR TEST
26 Rch Common Voltage Pin, 2.75V Test Pin (Internal Pull-down Pin, typ. 100kΩ)
VREFR+ VREFR
28 Rch Positive Reference Output Voltage, 3.75V
Normally connected to AGND with a large
electrolytic capacitor and connected to VREFR−
with a 0.22µF ceramic capacitor.
Rch Voltage Reference Input Pin, AVDD
Normally, conne cted to AVSS with a 10µF
electrolytic capacit or and a 0.1µF ceramic capacitor.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
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PIN / FUNCTION
No. Pin Name I/O Function
1 VREFL I Lch Voltage Reference Input Pin, AVDD
Normally, connected t o AVSS with a 10µF electrolytic capacitor and a 0.1µF
ceramic capacitor.
2 AVSS - Analog Ground Pin
3 VCOM O Common Voltage Output Pin, AVDD/2
4 LIN+ I Lch Analog Positive Input Pin
5 LIN− I Lch Analog Negative Input Pin
6 CKS0 I Master Clock Select 0 Pin (Internal Pull-down Pin, typ. 100kΩ)
7 DVDD - Digital Power Supply Pin, 3.0 ∼ 5.25V
8 DVSS - Digital Ground Pin
9 OVF O Analog Input Overflow Detect Pin
This pin goes to “H” if analog input overflows.
10 PDN I Power Down Mode Pin
“H”: Power up, “L”: Power down
11 DIF I Audio Interface Format Pin
“H” : 24bit I2S Compatible, “L” : 24b it MS B justified
12 M/S I Master / Slave Mode Pin
“H” : Master Mode, “L” : Slave Mode
13 LRCK I/O Output Channel Clock Pin
“L” Output in Master Mode at Power-down mode.
14 BICK I/O Audio Serial Data Clock Pin
“L” Output in Master Mode at Power-down mode.
15 SDTO O Audio Serial Data Output Pin
“L” Output at Power-down mode.
16 CKS1 I Master Clock Select 1 Pin (Internal Pull-down Pin, typ. 100kΩ)
17 MCLK I Master Clock Input Pin
18 DFS0 I Sampling Speed Select 0 Pin
19 HPFE I High Pass Filter Enable Pin
“H” : Enable, “L” : Disable
20 DFS1 I Sampling Speed Select 1 Pin
21 BVSS - Substrate Ground Pin
22 AVSS - Analog Ground Pin
23 AVDD - Analog Power Supply Pin, 4.75 ∼ 5.25V
24 RIN− I Rch Analog Negative Input Pin
25 RIN+ I Rch Analog Positive Input Pin
26 TEST I Test Pin (Internal Pull-down Pin, typ. 100kΩ)
27 AVSS - Analog Ground Pin
28 VREFR I Rch Voltage Reference Input Pin, AVDD
Normally, connected t o AVSS with a 10µF electrolytic capacitor and a 0.1µF
ceramic capacitor.
Note: All digital input pins except pull-down pins should not be left floating.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
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Handling of Unused Pin
The unused I/O pins should be processed appropriately as below.
Classification Pin Name Setting
LIN+, LIN− These pins should be connected to AVSS.
RIN+, RIN− These pins should be connected to AVSS.
Analog VREFL, VREFR These pins should be connected to AVDD.
OVF This pin should be open.
Digital TEST This pin should be connected to DVSS.
ABSOLUTE MAXIMUM RATINGS
(AVSS, BV SS, DVSS=0 V; Note 1)
Parameter Symbol min max Units
Power Supplies:
Analog
Digital
|BVSS – DVSS| (Note 2)
AVDD
DVDD
∆GND
−0.3
−0.3
-
6.0
6.0
0.3
V
V
V
Input Current, Any Pin Except Suppl ies IIN - ±10 mA
Analog Input Voltage (LIN+/–, RIN+/–, VREFL/R pins) VINA −0.3 AVDD+0.3 V
Digital Input Voltage (All digital input pins) VIND −0.3 DVDD+0.3 V
Ambient Temperature (Power applied)
28SOP Package
28VSOP Package Ta
Ta −10
−40 70
85 °C
°C
Storage Tem perature Tstg −65 150 °C
Note 1. All voltages with respect to ground.
Note 2. AVSS BVSS, and DVSS must be connected to the same analog ground plane.
WARNING: Operation at or beyond these limits may result in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
RECOMMENDED OPERATING CONDITIO NS
(AVSS, BV SS, DVSS=0V; No te 1 )
Parameter Symbol min typ max Units
Power Supplies
(Note 3) Analog
Digital AVDD
DVDD 4.75
3.0 5.0
3.3 5.25
AVDD V
V
Voltage Refere nce (VREFL/R pins) VREF 3.0 - AVDD V
Note 1. All voltages with respect to ground.
Note 3. The power up sequence between AVDD and DVDD is not critical.
WARNING: AKM assumes no responsibility for the usage beyond the conditions in this datasheet.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 8 -
ANALOG CHARACTERISTICS
(Ta=25°C; AVDD=5.0V, DVDD=3.3V; AVSS=BVS S=DVSS=0V; VREFL=VREFR=AVDD; fs=48kHz, 96kHz,
192kHz; BICK=64fs; Signal Frequency=1kHz; 24bit Data; Measurement frequency=20Hz ∼ 20kHz at fs=48kHz,
40Hz ∼ 40kHz at fs=96kHz, 40Hz ∼ 40kHz at fs=192kHz; unless otherwise specified)
Parameter min typ max Units
Analog Input Characteristics:
Resolution 24 Bits
Input Voltage (Note 4) ±2.7 ±2.9 ±3.1 Vpp
fs=48kHz
BW=20kHz
−1dBFS (Note 5)
−1dBFS
−20dBFS
−60dBFS
-
92
-
-
103
100
91
51
dB
dB
dB
dB
fs=96kHz
BW=40kHz
−1dBFS
−20dBFS
−60dBFS
90
-
-
98
86
46
dB
dB
dB
S/(N+D)
fs=192kHz
BW=40kHz
−1dBFS
−20dBFS
−60dBFS
-
-
-
98
86
46
dB
dB
dB
Dynamic Range (−60dBFS with A-weighted) 107 114 dB
S/N (A-weighted) 107 114 dB
Input Resistance 9 13 kΩ
Interchannel Isolat ion 100 120 dB
Interchannel Gain Mismatch 0.1 0.5 dB
Power Supply Rejection (Note 6) 50 - dB
Power Supplies
Power Supply Current
Normal Operation (PDN pin = “H”)
AVDD
DVDD (fs=48kHz)
DVDD (fs=96kHz)
DVDD (fs=192kHz)
Power down mode (PDN pin = “L”) (Note 7)
AVDD+DVDD
30
10
17
20
10
45
15
25
30
100
mA
mA
mA
mA
µA
Note 4. This value is (LIN+)−(LIN−) and (RIN+)−(RIN−). Input voltage is proportional to VREF voltage.
Vin = 0.58 x VREF (Vpp).
Note 5. 100µF capacitors are connected between the VREFL/R pins and AVSS.
Note 6. PSR is applied to AVDD and DVDD with 1kHz, 20m Vpp. The VREFL and VREFR pins held a constant voltage.
Note 7. All digital input pins are held DVDD or DVSS.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
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FILTER CHARACTERISTICS (fs=48kHz)
(Ta=25°C; AVDD=4.75 ∼ 5.25V; DVDD=3.0 ∼ 5.25V; DFS1 = “L”, DFS0 = “L”)
Parameter Symbol min typ max Units
ADC Digital Filter (Decimation LPF):
Passband (Note 8)
−0.005dB
−0.02dB
−0.06dB
−6.0dB
PB
0
-
-
-
22.038
22.2
24.0
21.5
-
-
-
kHz
kHz
kHz
kHz
Stopband SB 26.5 kHz
Passband Ripple PR ±0.005 dB
Stopband Attenuation SA 100 dB
Group Delay (Note 9) GD 43.2 1/fs
Group Delay Distortion ∆GD 0 µs
ADC Digital Filter (HPF):
Frequency Response (Note 8)
−3dB
−0.1dB FR
1.0
6.5
Hz
Hz
FILTER CHARACTERISTICS (fs=96kHz)
(Ta=25°C; AVDD=4.75 ∼ 5.25V; DVDD=3.0 ∼ 5.25V; DFS1 = “L”, DFS0 = “H”)
Parameter Symbol min typ max Units
ADC Digital Filter (Decimation LPF):
Passband (Note 8)
−0.005dB
−0.02dB
−0.06dB
−6.0dB
PB
0
-
-
-
44.081
44.5
48.0
43.0
-
-
-
kHz
kHz
kHz
kHz
Stopband SB 53.0 kHz
Passband Ripple PR ±0.005 dB
Stopband Attenuation SA 100 dB
Group Delay (Note 9) GD 43.1 1/fs
Group Delay Distortion ∆GD 0 µs
ADC Digital Filter (HPF):
Frequency Response (Note 8)
−3dB
−0.1dB FR
2.0
13.0
Hz
Hz
Note 8. The passband and stopband frequencies scale with fs. The reference frequency of these responses is 1kHz.
Note 9. The calculat ed delay time induced by digital filtering. This time is from the input of an analog signal to the
setting of 24bit data both channels to the ADC output register for ADC.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
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FILTE R CHAR ACTERIST I C S (fs=19 2kH z )
(Ta=25°C; AVDD=4.75 ∼ 5.25V; DVDD=3.0 ∼ 5.25V; DFS1 = “H”, DFS0 = “L”)
Parameter Symbol min typ max Units
ADC Digital Filter (Decimation LPF):
Passband (Note 8)
−0.005dB
−0.02dB
−0.06dB
−6.0dB
PB
0
-
-
-
88.183
89.0
96.0
86.0
-
-
-
kHz
kHz
kHz
kHz
Stopband SB 106.0 kHz
Passband Ripple PR ±0.005 dB
Stopband Attenuation SA 100 dB
Group Delay (Note 9) GD 38.2 1/fs
Group Delay Distortion ∆GD 0 µs
ADC Digital Filter (HPF):
Frequency Response (Note 8)
−3dB
−0.1dB FR
4.0
26.0
Hz
Hz
Note 8. The passband and stopband frequencies scale with fs. The reference frequency of these responses is 1kHz.
Note 9. The calculat ed delay time induced by digital filtering. This time is from the input of an analog signal to the
setting of 24bit data both channels to the ADC output register for ADC.
DC CHARACTERISTICS
(Ta=25°C; AVDD=4.75 ∼ 5.25V; DVDD=3.0 ∼ 5.25V)
Parameter Symbol min typ Max Units
High-Level Input Voltage
Low-Level Input Voltage VIH
VIL 70%DVDD
- -
- -
30%DVDD V
V
High-Level Output Voltage (Iout=−400µA)
Low-Level Output Voltage (Iout=400µA) VOH
VOL DVDD−0.4
- -
- -
0.4 V
V
Input Leakage Current (Note 10) Iin - - ±10 µA
Note 10. CKS1, CKS0 and TEST pins are internally connected to a pull-down resistor. (ty p. 100kΩ)
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
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SWITCHING CHARACTERISTICS
(Ta=25°C; AVDD=4.75 ∼ 5.25V; DVDD=3.0 ∼ 5.25V; CL=20pF)
Parameter Symbol min typ max Units
Master Clock Timing
Frequency
Pulse Width Low
Pulse Width High
fCLK
tCLKL
tCLKH
2.048
14.5
14.5
27.648
MHz
ns
ns
LRCK Frequency
Normal Speed Mode
Double Speed Mode
Quad Speed Mode
fsn
fsd
fsq
8
54
108
54
108
216
kHz
kHz
kHz
Duty Cycle
Slave mode
Master mode
45
50 55
%
%
Audio Interface Timing
Slave mode
BICK Period
Normal Speed Mode
Double Speed Mode
Quad Speed Mode
BICK Pulse Width Low
Pulse Width High
LRCK Edge to BI CK “↑” (Note 11)
BICK “↑” to LRCK Edge (Note 11)
LRCK to SDTO (MSB) (Except I2S mode)
BICK “↓” to SDTO
tBCK
tBCK
tBCK
tBCKL
tBCKH
tLRB
tBLR
tLRS
tBSD
1/128fsn
1/64fsd
1/64fsq
33
33
20
20
20
20
ns
ns
ns
ns
ns
ns
ns
ns
ns
Master mode
BICK Frequency
BICK Duty
BICK “↓” to LRCK
BICK “↓” to SDTO
fBCK
dBCK
tMBLR
tBSD
−20
−20
64fs
50
20
20
Hz
%
ns
ns
Reset Timing
PDN Pulse Width (Note 12)
PDN “↑” to SDTO valid (Note 13)
tPD
tPDV
150
516
ns
1/fs
Note 11. BICK rising edge must not occur at the same time as LRCK edge.
Note 12. The AK5385B can be reset by bringing the PDN pin = “L ”.
Note 13. This cycle is the number of LRCK rising edges from the PDN pin = “H”. This value is in master mode
This value is longer 1/fs in slave mode than master mode.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
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Timing Diagram
1/fCLK
MCLK
tCLKH tCLKL
VIH
VIL
1/fs
LRCK VIH
VIL
tBCK
BICK
tBCKH tBCKL
VIH
VIL
Clock Timing
LRCK VIH
VIL
tBLR
BICK VIH
VIL
tLRS
SDTO 50%DVDD
tLRB
tBSD
Audio Interface Timing (Slave mode)
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
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LRCK
BICK 50%DVDD
SDTO 50%DVDD
tBSD
tMBLR dBCK
50%DVDD
Audio Interface Timing (Master mode)
tPD
PDN VIL
PDN VIH
VIL
tPDV
SDTO 50%DVDD
Power Down & Reset Timing
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
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OPERATION OVERVIEW
System Clock
MCLK (256fs/384fs/512fs), BICK (48fs∼) and LR CK (fs) clocks are required in slave mode. T he LRCK clock input must
be synchronized with MCLK, however the phase is not critical. Table 1 shows the relationship of typical sampling
frequency and the sy stem cloc k frequency. M CLK frequenc y is se lect ed by CKS1-0 pi ns as shown in Table 2 and LRC K
frequency is selected by DFS1-0 pins as shown in Table 3.
As the AK5385B includes the phase detect circuit for LRCK, the AK5385B is reset automatically when the
synchronization is out of phas e by changing the clock frequenci es.
All external clocks (MCLK, BICK and LRCK) must be present unless PDN pin = “L”. If these clocks are not provided,
the AK5385B ma y draw excess current due to its use of internal dy namically re freshed logic. If the external clocks are not
present, place the AK5385B in power-down mode (PDN pin = “L”). In master mode, the m aster clock (MCLK) must be
provided unless PDN pin = “L”.
MCLK
fs 128fs 256fs 384fs 512fs
32kHz N/A 8.192MHz 12.288MHz 16.384MHz
44.1kHz N/A 11.2896MHz 16.9344MHz 22.5792MHz
48kHz N/A 12.288MHz 18.432MHz 24.576MHz
96kHz N/A 24.576MHz N/A N/A
192kHz 24.576MHz N/A N/A N/A
Table 1. System Clock Example
CKS1 pin CKS0 pin MCLK Frequency
L L 256fs
L H 128fs
H L 512fs
H H 384fs
Table 2. MCLK Frequency
DFS1 pin DFS0 pin LRCK Frequency
L L
8kHz ≤ fs ≤ 54kHz
L H
54kHz < fs ≤ 108kHz
H L
108kHz < fs ≤ 216kHz
H H N/A
Table 3. Sampling Speed
When changing MCLK frequency in master/slave mode, the AK5385B should reset by PDN pin = “L”. (ex.
12.288MHz(@fs=48kHz) t o 24.576MHz (@fs=96kHz) at CKS1 pin = CKS0 pin = “L”.
If the CKS1-0 and DFS1-0 pins are changed with same MCLK frequency in master/slave mode (ex. MCLK is fixed to
24.576MHz and fs is changed from 48kHz (CK S1 pin = “L”, CKS0 pin = “L”) to 96kHz (CKS1 pin = “L”, CKS0 pin =
“H”)), no reset by PDN pin = “L” is required.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 15 -
Audio Interface Format
Two kinds of data formats can be chosen with the DIF pin (Table 4). In both modes, the serial data is in MSB first, 2’s
complem ent form at. The SDTO i s clocked out on t he falling edge of BICK. The audio interface supports both m aster and
slave modes. In master mode, BICK and LRCK are output with the BICK frequency fixed to 64fs and the LRCK
frequency fixed to 1fs.
Mode DIF pin SDTO LRCK BICK Figure
0 L 24bit, MSB justifi ed H/L ≥ 48fs Figure 1
1 H 24bit, I2S Compatible L/H ≥ 48fs Figure 2
Table 4. Audio Interface Format
LRCK
BICK(64fs)
SDTO(o)
0
23 22
12
4 0
20 21 24 31 0 12
23 22 0
10
23
2220 21 31
23:MSB, 0:LSB
Lch Data Rch Data
24
321
22 23 23
1234
Figure 1. Mode 0 Timing
LRCK
BICK(64fs)
SDTO(o)
0
23 22
12
4 0
2521 24 0 12
23 22 0
1022 2521 24
321
22 23 23
1234
3
23:MSB, 0:LSB
Lch Data Rch Data
Figure 2. Mode 1 Timing
Master Mode and Slave Mode
The M/S pin selects either master or slave modes. M/S pin = “H” selects master mode and “L” selects slave mode. The
AK5385B outputs BICK and LRCK in master mode. In slave mode, provide MCLK, BICK and LRCK.
M/S pin Mode BICK, LRCK
L Slave Mode BICK = Input
LRCK = Input
H Master Mode BICK = Outpu t
LRCK = Output
Table 5. Master m ode/Slave m ode
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 16 -
Digital High Pass Filter
The ADC has a digital high pass fil ter for DC offset cancellation. The cut-off frequency of the HPF is 1.0Hz
(@fs=48kHz) and scales with sampling rate (fs).
HPF is controlle d by HPFE pin. If HPF setti ng (ON/OFF) is changed at operating, click noise occurs by changing DC
offset. It is recommended that HPF setting is changed at PDN pin = “L”.
Overflow Detection
The AK5385B has overflow detect function for analog input. OVF pin goes to “H” if Lch or Rch overflows (more than
−0.3dBFS). OVF output for overflowed anal og input has the same group delay as ADC (GD=43.2/fs=0.9ms@fs=48kHz).
OVF is “L” for 516/fs (=10.75ms@fs=48kHz) after PDN pin = “↑”, and then overflow detection is enabled.
Power Down and Reset
The AK5385B is pla ce d i n the powe r-dow n m ode by bringing PDN pin “L” and the digita l fi l te r is al so re se t at the same
time. This reset should always be done after power-up. In the power-down mode, the VCOM is AGND level. An analog
initialization cycle starts after exiting the power-down mode. Therefore, the output data SDTO becomes available after
516 cycles of LRCK clock i n maste r mode (517 cy cles in slave mode). Duri ng initial ization, the ADC digit al data out puts
of both channels are forced to “0”. The ADC outputs settle in the data corresponding to the input signals after the end of
initialization (Settling approximately takes the group delay time).
The AK5385B should be reset once by bringing PDN pin “L” after power-up. The internal timing starts clocking by the
rising edge (falling edge at Mode 1) of LRCK after exiting from reset and power down state by MCLK.
Normal Operation
Internal
State
PDN
Powe r-down Initialize Normal Operation
(1)
Idle N o is e
GD GD
“0”data
A
/D In
(Analog)
A
/D Out
(Digital)
Clock In
MCLK,LRCK,SCLK
(2)
(3)
(4)
“0”data Idle Noise
Notes:
(1) 517/fs in slave mode and 516/fs in master mode.
(2) Digital output corresponding to analog input has the group delay (GD).
(3) A/D output is “0” data at the power-down state.
(4) When the external clocks (MCLK, SCLK, LRCK) are stopped, the AK5385B should be in the power-down state.
Figure 3. Power-down/up sequence example
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 17 -
SYSTEM DESIGN
Figure 4 shows the syste m connecti on diagram. An e valuation board is avai lable which demonst rates application ci rcuits,
the optimum layout, power supply arrangements and measurement results.
0.1µ
10µ
0.1µ
10µ
VREFL1
2
3
4
5
6
7
8
9
10
11
AVSS
VCOM
LIN+
LIN-
CKS0
DVDD
DVSS
OVF
PDN
DIF
AK5385B
DSP an d uP
28
27
26
VREFR
AVSS
TEST
Digital Supply
3.0 ~ 5.25V
12 M/S
13 LRCK
14 BICK
Reset
25
24
RIN+
RIN-
23
22
AVDD
AVSS
21
20
BVSS
DFS1
19
18
HPFE
DFS0
17
16
MCLK
CKS1
15SDTO
Analog Supply
4.75 ~ 5.25V
0.1µ
10µ
0.22µ
0.1µ
10µ
Note:
- AVSS, BVSS and DVSS of the AK5385B should be distributed separately from the ground of external digita l
devices (MPU, DSP etc.).
- All input pins except pull-down (CKS0, CKS1 and TEST pin) pin should not be left floating.
Figure 4. Typical Connection Diagram
Analog Ground Digital Ground
System
Controller
1
2
3
4
5
6
7
8
9
10
11
12
28
27
26
25
24
23
22
21
20
19
18
17
14
16
15
VREFL
AVSS
VCOM
LIN+
LIN-
CKS0
DVDD
DVSS
OVF
DIF
M/S
VREFR
A
VSS
TEST
RIN+
RIN-
AVDD
A
VSS
BVSS
DFS1
HPFE
DFS0
MCLK
AK5385B
LRCK
BICK
CKS1
SDTO
PDN
13
Figure 5. Ground Layout
Note:
- AVSS BVSS, and DVSS must be connected to the same analog ground plane.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 18 -
1. Grounding and Power Supply Decoupling
The AK5385B requires careful attention to power supply and grounding arrangements. Alternatively if AVDD and
DVDD are suppl ied separately, t he power up sequence is not critical . AVSS, BVSS and DVSS of the AK5385B mu st be
connected to analog ground plane. System analog ground and digital ground should be connected together near to
where the supplies are brought ont o the printed circuit board. Decoupling capaci tors should be as near to the AK5385B as
possible, with the small value ceramic capacitor being the nearest.
2. Voltage Reference Inputs
The reference voltage for A/D converter is supplied from VREFL/R pins at AVSS reference. AVSS pin is connected to
analog ground and an elect rolytic capacitor over 10 µF parallel with a 0.1µF ceramic capacit or between the VREFL/R pins
and the AVSS pin eliminate the effects of high frequency noise. Especially, a ceramic capacitor should be as near to the
pins as possibl e. A nd all di gital signal s, espec iall y c locks, shoul d be kept away from the VREFL/ R pi ns in orde r to a void
unwanted coupling into the AK5385B. No load current may be taken from the VREFL/R pins.
VCOM is a signal ground of this chip. An electrolytic capacitor 0.22µF attached to VCOM pin eliminates the effects of
high frequency noise. No load current may be drawn from the VCOM pin. All signals, especially clocks, should be kept
away from the VCOM pin in order to avoid unwanted coupling into the AK5385B.
3. Analog Inputs
Analog signal is differentially input into the m odulator via the LIN+ (RIN+ ) and the LIN− (RIN−) pins. The input voltage
is the diffe rence betwee n the LIN+ (RIN+ ) and LIN− (RIN−) pins. The ful l sca le of eac h pi n i s nominally ±2.9Vpp(typ).
The AK5385B can accept input volt ages from AVSS to AVDD. The ADC output dat a format is 2’s complement. The
internal HPF removes the DC offset.
The AK5385B sam ples the analog inputs at 128fs (6.144M Hz@fs=48kHz, Normal Speed Mode ). The digital filter rejec ts
noise above the stop band except for multiples of 128fs. The AK5385B includes an anti-aliasing filter (RC filter) to
attenuate a noise around 128fs.
The AK5385B accepts +5V supply voltage. Any volt a ge which exceeds the upper limit of AVDD+0.3V and lower limit
of AVSS−0.3V and any c urrent beyond 10mA for the analog input pi ns (LIN+/−, RIN+/−) should be avoided. Excessive
currents to the input pins may damage the device. Hence input pins mu st be protected from signals at or beyond these
limits. Use caution specially in case of using ±15V in other anal og circuits.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 19 -
4. External Anal og Circuit Exampl es
Figure 6 shows an input buffer c ircuit example 1. This is a full-different ial input buffer circuit w ith an inverted-amp (ga in:
−10dB). The capacitor of 10nF between LIN+/− (RIN+/−) decreases the clock feed through noise of modulator, and
composes a 1st order LPF (fc=360kHz) with 22Ω resistor before the capacitor. This circuit also has a 1st order LPF
(fc=370kHz) composed of op-amp. The evaluation board should be referred about the detail.
4
5
LIN+
LIN-
AK5385B
Analog In 4.7k
4.7k
VP+
VP-
NJM5532
47µ3k
470p
910
22
47µ3k
470p
910
22
Bias
10n
9.56Vpp
2.9Vpp
2.9Vpp
Bias
10µ0.1µBias
10k
10k
VA
VA = 5V
VP+ = 15V
VP- = -15V
Figure 6.Input Buffer example
Figure 7 shows an input buffer circuit exampl e 2. (1st order HPF: fc=0.66Hz, Table 6; 1st order LPF: fc=590kHz,
gain=−14dB, Table 7). The analog signal is able to input through XLR or BNC connectors. (short JP1 and JP2 for BNC
input, open JP1 and JP2 for XLR input). The input level of this circuit is +/−14.7Vpp.
BNC
NJM5534
4
5
LIN+
LIN-
AK5385B
4.7k
4.7k
JP1
JP2
91
91
1.5n
2.9Vpp
NJM5534
NJM5534
1k
22µ1k
22µ
10k
10k
4.7k
4.7k
VA
10µ
0.1µ
Vin-
Vin+
XLR 100
2.9Vpp
14.7Vpp
14.7Vpp
Bias
Figure 7.Input Buffer example
fin 1Hz 10Hz
Frequency Response −1.56dB −0.02dB
Table 6. Frequency Response of HPF
fin 20kHz 40kHz 6.144MHz
Frequency Response −0.005dB −0.02dB −15.6dB
Table 7. Frequency Response of LPF
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 20 -
5. Measurem ent Exa mple
Figure 8 shows the S/ (N+D) vs. VR EF capaci tor that i s connected be tween VREFL/R pins and AVSS pin wit h the 0.1µF
capacitor in parallel . X - A X IS is the capacity for VREF; Y- AXIS is S/(N+ D).
[Measurement Condition]
- AVDD = 5.0V, DVDD = 3.3V; AVSS = BVSS = DVS S = 0V
- fs = 48kHz
- Measurement Bandwidth = 10Hz ∼ 20kHz
- Ta = 25°C
- Using Audio Precision System Two Cascade
S/(N+D) vs. VREF Cap
100.0
101.0
102.0
103.0
104.0
105.0
106.0
0 50 100 150 200 250
VREF Cap [uF]
S/(N+D) [dB]
Lch Rch
Figure 8. S/(N+D) vs. VREF Cap
6. Synchronization of Multiple Devices
In system where multiple ADCs are required, care must be taken to achieve simultaneous sampling. To ensure
synchronous sampling, the MCLK and LRCK must be the same for all of the AK5385Bs in the system. The all
AK5385Bs should be reset at the same timing wit h preventing the reset signal for AK5385B from overlapping on the edge
of MCLK, so that all AK5385Bs begin sampling on the same clock edge.
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 21 -
PACKAGE (AK5385BVF)
0.1±0.1
0-10°
Detail A
Seating Plane
NO TE: Dimension "*" does not include mold fla sh.
| 0.10
0.15-0.05
0.22±0.1 0.65
*9.8±0.2 1.25±0.2
A
114
15
28
28pin VS OP (Unit: m m)
*5.6±0.2
7.6±0.2
0.5±0.2
+0.1
0.675
Material & Lead finish
Package molding compound: Epoxy
Lead frame material: Cu
Lead frame surface treatment: Solder (Pb free) plate
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 22 -
PACKAGE (AK5385BVS)
0-10°
0.10
0.15-0.05
1.095TYP
18.7±0.3
28pin SO P (Unit: m m )
7.5 ± 0.2
0.75 ± 0.2
+0.1
10.4 ± 0.3
2.2 ± 0.1
1.27
0.12 M
+0.1
0.1-0.05
0.4±0.1
Material & Lead finish
Package molding compound: Epoxy
Lead frame material: Cu
Lead frame surface treatment: Solder (Pb free) plate
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 23 -
MARKING (AK5385BVF)
AKM
A
K5385BVF
XXXBYYYYC
XXXBYYYYC Date code identi fier
XXXB : Lot number (X : Digit number, B : Alpha character)
YYYYC : Assembly date (Y : Digit number, C : Alpha character)
ASAHI KASEI [AK5385B]
MS0406-E-00 2005/08
- 24 -
MARKING (AK5385BVS)
AKM
A
K5385BVS
XXXBYYYYC
XXXBYYYYC Date code identi fier
XXXB : Lot number (X : Digit number, B : Alpha character)
YYYYC : Assembly date (Y : Digit number, C : Alpha character)
Revision History
Date (YY/MM/DD) Revision Reason Page Contents
05/08/10 00 First Edition
IMPORTANT NOTICE
• These products and their specifications ar e subject to change without notice. Before considering
any use or application, consult the Asahi Kasei Micros ystems Co., Ltd. (AKM) sales office or
authorized distributor conc erning their current status.
• AKM assumes no liability for infringe ment of any patent, intellectual property, or other right in the
application or use of any information contained her ein.
• Any export of these products, or devices or systems containing them, may require an export license
or other official approval under the law and regulations of the country of export pertaining to customs
and tariffs, currency exchange, or strategic ma terials.
• AKM products are neither intended nor authorized for use as critical components in any safety, life
support, or other hazard related device or system, and AKM assumes no responsibility relating to any
such use, except with the express w ritten consent of the Representative Director of AKM. As used
here:
a. A hazard related device or system is one designed or intended for life support or maintenance of
safety or for applications in medicine, aerospace, nuclear energy, or other fields, in which its
failure to function or perform may reasonably be expected to result in loss of life or in significant
injury or damage to person or property.
b. A critical component is one whose failure to function or perform may reasonably be expected to
result, whether directly or indirectly, in the loss of the safety or effectiveness of the device or
system containing it, and which must therefore meet very high s tandards of performance and
reliability.
• It is the responsibility of the buyer or distributor of an AKM pr oduct who distributes, disposes of, or
otherwise places the produc t with a third party to notify that party in advance of the above content
and conditions, and the buyer or distribu tor agrees to assume any and all responsibility and liability
for and hold AKM harmless from any and all claims arising from the use of said product in the
absence of such notification.
