ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 1 -
GENERAL DESCRIPTION
The AK4385 offers the perfect mix for cost and performance based audio systems. Using AKM's multi bit
architecture for its modulator the AK4385 delivers a wide dynamic range while prese rvi ng linearity for
improved THD+N performance. The AK4385 has full differential SCF outputs, removing the need for AC
coupling capacitors and increasing performanc e for syst ems with excessive clo ck jitter. The 24 Bit word
length and 192kHz sampling rate make this part ideal for a wide ran ge of applications including
DVD-Audio. The AK4385 i s offered in a spac e saving 16pin TSSOP package.
FEATURES
Sampling Rate Ranging from 8kHz to 192kHz
128 times Oversampling (Normal Speed Mo de)
64 times Oversampling (Double Speed Mode)
32 times Oversamp ling (Quad Speed Mode)
24-Bit 8 times FIR Digital Filter
On chip SCF
Digital de-emphasis for 32k, 44.1k and 48kHz sampling
Soft mute
Digital Attenuator (Linear 256 steps)
I/F format: 24-Bit MSB justified, 24/20/16-Bit LSB justified or I2S
Master clock: 256fs, 384fs, 512fs or 768fs (Normal Speed Mode)
128fs, 192fs, 256fs or 384fs (Double Speed Mode)
128fs, 192fs (Quad Spe ed Mode)
THD+N: -94dB
Dynamic Range: 108dB
High Tolerance to Clock Ji tter
Power supply: 4.75 to 5.25V
Very Small Package: 16pin TSSOP (6.4mm x 5.0mm)
AK4381 Pin Compatible
LRCK
BICK
SDTI
Audio
Data
Interface
MCLK
PDN
∆Σ
Modulator AOUTL+
8X
Interpolator SCF
AOUTR+
SCF
V
DD
V
SS
De-emphasis
Control
µP
Interface
Clock
Divider
CSN
CCLK
CDTI
DZFR
∆Σ
Modulator
8X
Interpolator
AOUTL-
AOUTR-
DZFL
108dB 192kHz 24-Bit 2ch ∆Σ DAC
AK4385
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 2 -
Ordering Guide
AK4385VT -40 ∼ +85°C 16pin TSSOP (0.65mm pitch)
AKD4385 Evaluation Board for AK4385
Pin Layout
1
MCLK
LRCK
BICK
CSN
CCLK
CDTI
Top
View
2
3
4
5
6
7
8
DZFL
DZFR
VSS
VDD
A
OUTL+
A
OUTL-
A
OUTR+
A
OUTR-
16
15
14
13
12
11
10
9
PDN
SDTI
PIN/FUNCTION
No. Pin Name I/O Function
1 MCLK I Master Clock Input Pin
An external TTL clock should be input on this pin.
2 BICK I Audio Serial Data Clock Pin
3 SDTI I Audio Serial Data Input Pin
4 LRCK I L/R Clock Pin
5 PDN I Power-Down Mode Pin
When at “L”, the AK4385 is in the power-down mode and is held in reset.
The AK4385 should always be reset upon power-up.
6 CSN I Chip Select Pin
7 CCLK I Control Data Input Pin
8 CDTI I Control Data Input Pin in serial mode
9 AOUTR- O Rch Negative Analog Output Pin
10 AOUTR+ O Rch Positive Ana lo g O utput Pin
11 AOUTL- O Lch Negative Analog Output Pi n
12 AOUTL+ O Lch Positive Analog Output Pin
13 VSS - Ground Pin
14 VDD - Power Supply Pin
15 DZFR O Rch Data Zero Input Detect Pin
16 DZFL O Lch Data Zero Input De tect Pin
Note: All input pins should not be left floating.
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 3 -
ABSOLUTE MAXIMUM RATINGS
(VSS=0V; Note 1)
Parameter Symbol min max Units
Power Supply VDD -0.3 6.0 V
Input Current (any pins except for supplies) IIN - ±10 mA
Input Voltage VIND -0.3 VDD+0.3 V
Ambient Operat ing Temperature Ta -40 85 °C
Storage Tem perature Tstg -65 150 °C
Note: 1. All voltages with respect to ground.
WARNING: Operation at or beyond these limits may results in permanent damage to the device.
Normal operation is not guaranteed at these extrem es.
RECOMMENDED OPERATING CONDI TIONS
(VSS=0V; Note 1)
Parameter Symbol min typ max Units
Power Supply VDD 4.75 5.0 5.25 V
*AKM assumes no responsibility for the usage beyond the conditions in this datasheet.
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 4 -
ANALOG CHARACTERISTICS
(Ta=25°C; VDD=5.0V; fs=44.1kHz; BICK=64fs; Si gnal Frequency=1kHz ; 24bit Input Data;
Measurement frequency=20Hz ∼ 20kHz; RL ≥4kΩ; unless otherwise specified)
Parameter min typ max Units
Resolution 24 Bits
Dynamic Characteristics (Note 3)
fs=44.1kHz
BW=20kHz 0dBFS
-60dBFS -94
-44 -84
- dB
dB
fs=96kHz
BW=40kHz 0dBFS
-60dBFS -92
-41 -
- dB
dB
THD+N
fs=192kHz
BW=40kHz 0dBFS
-60dBFS -92
-41 -
- dB
dB
Dynamic Range (-60dBFS with A-weighted) (Note 4) 100 108 dB
S/N (A-weighted) (Note 5) 100 108 dB
Interchannel Isolation (1kHz) 90 110 dB
Interchannel Gain Mismatch 0.2 0.5 dB
DC Accuracy
Gain Drift 100 - ppm/°C
Output Volta ge (Note 6) ±2.55 ±2.75 ±2.95 Vpp
Load Resistance (Note 7) 4 kΩ
Power Supplies
Power Supply Current (VDD)
Normal Operation (PDN = “H”, fs≤96kHz)
Normal Operation (PDN = “H”, fs=192kHz)
Power-Down Mode (PDN = “L”) (Note 8)
17
20
10
27
32
100
mA
mA
µA
Notes: 3. Measured by Audio Precision (System Two). Refer to the evaluation board manual.
4. 100dB at 16bit data.
5. S/N does not depend on input bit length.
6. Full-scale voltage (0dB). Output voltage scales with the voltage of VREF,
AOUT (typ.@0dB)=(AOUT+)-(AOUT-)=±2.75Vpp × VREF/5.
7. For AC-load. 4kΩ for DC-load.
8. All digital inputs including clock pins (MCLK, BICK and LRCK) are held VDD or VSS.
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 5 -
SHARP ROLL-OFF FILTER CHARACTERISTICS
(Ta = 25°C; VDD = 4.75 ∼ 5.25V; fs = 44.1kHz; DEM = OFF; SLOW = “0”)
Parameter Symbol min typ max Units
Digital filter
Passband ±0.05dB (Note 9)
-6.0dB PB 0
-
22.05 20.0
- kHz
kHz
Stopband (Note 9) SB 24.1 kHz
Passband Ripple PR ± 0.02 dB
Stopband Attenuation SA 54 dB
Group Delay (Note 10) GD - 19.3 - 1/fs
Digital Fi lter + S CF
Frequency Response
20.0kHz
40.0kHz
80.0kHz
fs=44.1kHz
fs=96kHz
fs=192kHz
FR
FR
FR
-
-
-
± 0.2
± 0.3
+0.1/-0.6
-
-
-
dB
dB
dB
Notes: 9. The passband and stopband frequencies scale with fs(system sampling rate).
For example, PB=0.4535×fs (@±0.05dB), SB=0.546×fs.
10. The calculating delay time which occurred by digital filtering. This time is from setting the 16/24bit data
of both channels to input register to the output of analog signal.
SLOW ROLL-OFF FILTER CHARACTERISTICS
(Ta = 25°C; AVDD, DVDD = 4.75~5.25V; fs = 44.1kHz; DEM = OFF; SLOW = “1”)
Parameter Symbol min typ max Units
Digital Fi lter
Passband ±0.04dB (Note 11)
-3.0dB PB
0
-
18.2 8.1
- kHz
kHz
Stopband (Note 11) SB 39.2 kHz
Passband Ripple PR ± 0.005 dB
Stopband Attenuation SA 72 dB
Group Delay (Note 10) GD - 19.3 - 1/fs
Digital Fi lter + S CF
Frequency Response
20.0kHz
40.0kHz
80.0kHz
fs=44.kHz
fs=96kHz
fs=192kHz
FR
FR
FR
-
-
-
+0/-5
+0/-4
+0.1/-5
-
-
-
dB
dB
dB
Note: 11. The passband and stopband frequencies scale with fs.
For example, PB = 0.185×fs (@±0.04dB), SB = 0.888×fs.
DC CHARACTERISTICS
(Ta=25°C; VDD=4.75 ∼ 5.25V)
Parameter Symbol min typ max Units
High-Level Input Voltage
Low-Leve l Input Vo lt ag e VIH
VIL 2.2
- -
- -
0.8 V
V
High-Level Output Vol tage (Iout=-80µA)
Low-Level Output Voltage (Iout=80µA) VOH
VOL VDD-0.4
- - -
0.4 V
V
Input Leakage Current Iin - - ± 10 µA
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 6 -
SWITCHING CHARACTERISTICS
(Ta=25°C; VDD=4.75 ∼ 5.25V; CL=20pF)
Parameter Symbol min typ max Units
Master Clock Frequency
Duty Cycle fCLK
dCLK 2.048
40 11.2896
36.864
60 MHz
%
LRCK Frequency
Normal Speed Mode
Double Speed Mode
Quad Speed Mode
Duty Cycle
fsn
fsd
fsq
Duty
8
60
120
45
48
96
192
55
kHz
kHz
kHz
%
Audio Inte rface Timing
BICK Period
Normal Speed Mode
Double/Quad Speed Mode
BICK Pulse Width Low
Pulse Width High
BICK rising to LRCK Edge (Note 12)
LRCK Edge to BICK rising (Note 12)
SDTI Hold Time
SDTI Setup Tim e
tBCK
tBCK
tBCKL
tBCKH
tBLR
tLRB
tSDH
tSDS
1/128fs
1/64fs
30
30
20
20
20
20
ns
ns
ns
ns
ns
ns
ns
ns
Control Interf ace Timing
CCLK Period
CCLK Pulse Width Low
Pulse Width High
CDTI Setup Time
CDTI Hold Time
CSN “H” Time
CSN “↓” to CCLK “↑”
CCLK “↑” to CSN “↑”
tCCK
tCCKL
tCCKH
tCDS
tCDH
tCSW
tCSS
tCSH
200
80
80
40
40
150
50
50
ns
ns
ns
ns
ns
ns
ns
ns
Reset Timing
PDN Pulse Width (Note 13)
tPD
150
ns
Notes: 12. BICK rising edge must not occur at the same time as LRCK edge.
13. The AK4385 can be reset by bringing PDN= “L”.
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 7 -
Timing Diagram
1/fCLK
tCLKL
VIH
tCLKH
MCLK VIL
dCLK=tCLKH x fCLK, tCLKL x fCLK
1/fs
VIH
LRCK VIL
tBCK
tBCKL
VIH
tBCKH
BICK VIL
Clock Timing
tLRB
LRCK
VIH
BICK VIL
tSDS
VIH
SDTI VIL
tSDH
VIH
VIL
tBLR
Serial Interface Timing
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 8 -
tCSS
CSN
VIH
CCLK VIL
VIH
CDTI VIL
VIH
VIL
C1 C0 R/W A4
tCCKL tCCKH
tCDS tCDH
WRITE Command Input Timing
CSN
VIH
CCLK VIL
VIH
CDTI VIL
VIH
VIL
D3 D2 D1 D0
tCSW
tCSH
WRITE Data Input Timing
tPD
VIL
PDN
Power-down Timi ng
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 9 -
OPERATION OVERVIEW
System Clock
The external cloc ks, which are required to operat e the AK4385, are MCLK, LRC K and BICK. The master clock (MC LK)
should be synchronized with LRCK but the phase is not critical. The MCLK is used to operate the digital interpolation
filter and t he delta-sigm a m odulat or. There are t wo met hods to set M CLK frequency. In Manual Set ting Mode (ACKS =
“0”: Register 00H), the sam pling speed is set by DFS0/1(Ta ble 1). The frequency of MCLK at each sampling speed is set
automatically. (Table 2~4).After exiting reset (PDN = “↑”), the AK4385 is in Auto Setting Mode. In Auto Sett ing M ode
(ACKS = “1”: Default), as MCLK frequency is detected automatically (Table 5), and the internal master clock becomes
the appropriate frequency (Table 6), it is not necessary to set DFS0/1.
All externa l clocks (MCLK,BICK and LR CK) should always be present whenever the AK4385 is in the norma l operation
mode (P DN= ”H”). If these cl ocks are not provided, the AK4385 may draw excess current and m ay fall into unpredi ctable
operation. This is because the device utilizes dynamic refreshed logic internally. The AK4385 should be reset by PDN=
“L” after threse clocks are provided. If the external clocks are not present, the AK4385 should be in the powe r-down
mode (P DN= “L” ). Aft er exit ing reset at power-up e tc., the A K4385 is i n the power-down mode until MC LK and LRCK
are input.
DFS1 DFS0 Sampling Rate (fs)
0 0 Normal Speed Mode 8kHz~48kHz Default
0 1 Double Speed Mode 60kHz~96kHz
1 0 Quad Speed Mode 120kHz~192kHz
Table 1. Sampling Speed (Manual Setting Mode)
LRCK MCLK BICK
fs 256fs 384fs 512fs 768fs 1152fs 64fs
32.0kHz 8.1920MHz 12.2880MHz 16.3840MHz 24.5760MHz 36.8640MHz 2.0480MHz
44.1kHz 11.2896MHz 16.9344MHz 22.5792MHz 33.8688MHz N/A 2.8224MHz
48.0kHz 12.2880MHz 18.4320MHz 24.5760MHz 36.8640MHz N/A 3.0720MHz
Table 2. System Clock Example (Normal Speed Mode @Manual Setting Mode)
LRCK MCLK BICK
fs 128fs 192fs 256fs 384fs 64fs
88.2kHz 11.2896MHz 16.9344MHz 22.5792MHz 33.8688MHz 5.6448MHz
96.0kHz 12.2880MHz 18.4320MHz 24.5760MHz 36.8640MHz 6.1440MHz
Table 3. System Clock Example (Double Speed Mode @Manual Setting Mode)
LRCK MCLK BICK
fs 128fs 192fs 64fs
176.4kHz 22.5792MHz 33.8688MHz 11.2896MHz
192.0kHz 24.5760MHz 36.8640MHz 12.2880MHz
Table 4. System Clock Example (Quad Speed Mode @Manual Setting Mode)
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 10 -
MCLK Sampling Speed
512fs 768fs Normal
256fs 384fs Double
128fs 192fs Quad
Table 5. Sampling Speed (Auto Sett ing Mode: Default)
LRCK MCLK (MHz)
fs 128fs 192fs 256fs 384fs 512fs 768fs
Sampling Speed
32.0kHz - - - - 16.3840 24.5760
44.1kHz - - - - 22.5792 33.8688
48.0kHz - - - - 24.5760 36.8640
Normal
88.2kHz - - 22.5792 33.8688 - -
96.0kHz - - 24.5760 36.8640 - - Double
176.4kHz 22.5792 33.8688 - - - -
192.0kHz 24.5760 36.8640 - - - - Quad
Table 6. System Clock Example (Auto Setting Mode)
Audio Serial Interface Format
Data is shifted in via the SDTI pin using BICK and LRCK inputs. The DIF0-2 as shown in Table 7 can select five serial
data modes. In all modes the serial data is MSB-first, 2’s compliment format and is latched on the rising edge of BICK.
Mode 2 can be used for 16/20 MSB justified form ats by zeroing the unused LSBs.
Mode DIF2 DIF1 DIF0 SDTI Format BICK Figure
0 0 0 0 16bit LSB Justified
≥32fs Figure 1
1 0 0 1 20bit LSB Justified
≥40fs Figure 2
2 0 1 0 24bit MSB Justified ≥48fs Figure 3 Default
3 0 1 1 24bit I2S Compatible ≥48fs Figure 4
4 1 0 0 24bit LSB Justified
≥48fs Figure 2
Table 7. Audio Data Formats
SDTI
BICK
LRCK
SDTI 15 14 6 5 4
BICK
0 1 10 11 12 13 14 15 0 1 10 11 12 13 14 15 0 1
3 2 1 0 15 14
(
32fs
)
(
64fs
)
014
115 16 17 31 0 1 14 15 16 17 31 0 1
15 14 0 15 14 0
Mode 0 Don’t care Don’t care
15:MSB, 0:LSB
Mode 0 15 14 6 5 4 3 2 1 0
Lch Data Rch Data
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 11 -
Figure 1. Mode 0 Timing
SDTI
LRCK
BICK
(
64fs
)
091 10 11 12 31 0 1 9 10 11 12 31 0 1
19 0 19 0
Mode 1 Don’t care Don’t care
19:MSB, 0:LSB
SDTI
Mode 4 23:MSB, 0:LSB
20 19 0 20 19 0
Don’t care Don’t care
22 21 22 21
Lch Data Rch Data
8
23 23
8
Figure 2. Mode 1,4 Timing
LRCK
BICK
(
64fs
)
SDTI
0221 2 24 31 0 1 31 0 1
23:MSB, 0:LSB
22 1 0 Don’t care
23
Lch Data Rch Data
23 30 2222423 30
22 1 0Don’t care
23 22
23
Figure 3. Mode 2 Timing
LRCK
BICK
(
64fs
)
SDTI
031 2 24 31 0 1 31 0 1
23:MSB, 0:LSB
22 10Don’t care
23
Lch Data Rch Data
23 25 322423 25
22 1 0Don’t care
23 23
Figure 4. Mode 3 Timing
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 12 -
De-emphasis Filter
A digital de-emphasis filter is available for 32, 44.1 or 48kHz sampling rates (tc = 50/15µs) and is enabled or disabled
with DEM0 and DEM1. In case of double speed and quad speed mode, the digital de-emphasis filter is always off.
DEM1 DEM0 Mode
0 0 44.1kHz
0 1 OFF
Default
1 0 48kHz
1 1 32kHz
Table 8. De-emphasis Filter Control (Normal Speed Mode)
Output Volume
The AK4385 includes channel independent digital output volumes (ATT) w ith 256 levels at linear step including MUTE.
These volumes are in front of the DAC and can attenuate the input data from 0dB to –48dB and mute. When changing
levels, transitions are executed via soft changes; thus no switching noise occurs during these transitions. The transition
time of 1 level and all 256 levels is shown in Table 9.
Transition Time
Sampling Speed 1 Level 255 to 0
Normal Speed Mode 4LRCK 1020LRCK
Double Speed Mode 8LRCK 2040LRCK
Quad Speed Mode 16LRCK 4080LRCK
Table 9. ATT Transition Time
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 13 -
Zero Detection
The AK4385 has channel-independent zeros detect function. When the input data at each channel is continuously zeros
for 8192 LRCK cycle s, DZF pi n of each channe l goes to “H”. DZF pin of each channel im mediatel y goes to “L” if input
data of eac h cha nnel i s not zero a ft er going DZF “H” . If RS TN bi t i s “0” , DZF pins of bot h cha nnel s go t o “H”. DZF pin
of both channels go to “L ” at 2~3/fs after RSTN bit returns to “1”. If D ZFM bit is set t o “1”, DZF pins of both channels go
to “H” only when the i nput data at bot h channel s are conti nuously zeros for 8192 LRCK cycl es. Zero detect functi on can
be disabled by DZFE bit . In this ca se, DZF pins of both cha nnels are alway s “L”. DZFB bit can invert the polarity of DZF
pin.
Soft Mute Operation
Soft mute operation i s performed at digita l domain. When the SMUTE bit goes to “1” , the output signal is attenua ted by
-∞ during ATT_DATA×ATT transition time ( Tab le 9) fro m the c ur re nt ATT le vel . W he n th e S MU TE bi t is r etu rn ed to
“0”, the mute is cancelled and the output attenuation gradually changes to the ATT level during ATT_DATA×ATT
transition time. If the soft mute is cancelled before attenuating to -∞ after starting the operation, the attenuation is
discontinued and returned to ATT level by the same cycle. The soft mute is effective for changing the signal source
without stopping the signal transmission.
SMUTE bit
A
ttenuation
DZF pin
ATT Level
-∞
A
OUT
8192/fs
GD GD
(1)
(2)
(3)
(4)
(1)
Notes:
(1) ATT_DATA×ATT transition t i m e (Ta ble 9). F or e xample, in Normal Speed Mode , this t ime is 1020LRC K cy cl es
(1020/fs) at ATT_DATA=255.
(2) The analog output corresponding to the digital input has a group delay, GD.
(3) If the soft mute is cancelled before attenuating to -∞ after starting the operat ion, the atte nuation is discontinued and
retur n ed to ATT leve l b y the same cycle.
(4) When the input data a t each channel is continuously ze ros for 8192 LRCK cycl es, DZF pin of each cha nnel goes to
“H”. DZF pin immediately goes to “L” if input data are not zero after going DZF “H”.
Figure 5. Soft Mute and Zero Detection
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 14 -
System Reset
The AK4385 should be reset once by bringing PDN= ”L” upon power-up. The AK4385 is powered up and the internal
timing starts clocking by LRCK “↑” after exiting reset and power down state by MCLK. The AK4385 is in the
power-down mode until MCLK and LRCK are input.
Power-down
The AK4385 is placed in the power-down mode by bringing PDN pin “L” and the anlog outputs are floating (Hi-Z).
Figure 6 shows an example of the system timing at the power-down and power-up.
Normal Operation
Internal
State
PDN
Power-down Normal Operation
GD GD
“0” dat a
D/A Out
(Analog)
D/A In
(Digital)
Clock In
MCLK, LRCK, BICK
(1) (3)
(6)
DZFL/DZFR
External
MUTE (5)
(3) (1)
Mute ON
(2)
(4)
Don’t care
Notes:
(1) The analog output corresponding to digital input has the group delay (GD).
(2) Analog outputs are floating (Hi -Z) at the power-down mode.
(3) Click noise occurs at the e dge of PDN signal. This noise is output even if “0” data is input.
(4) The external clocks (MCLK, BICK and LRCK) can be stopped in the power-down mode (PDN = “L”).
(5) Please mute the analog output externally if the cl ick noise (3) influences syste m applicat ion.
The timing example is shown in this figure.
(6) DZF pins are “L” in the power-down mode (PDN = “L”).
Figure 6. Power-down/up Sequence Example
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 15 -
Reset Function
When RSTN=0, DAC is powered down but the internal register values are not ini tialized. The anal og outputs go to
VCOM voltage and DZF pin goes to “H”. Figure 7 shows the exa mple of reset by RSTN bit.
Internal
State
RSTN bit
Digital Block Power-down Normal Operati on
GD GD
“0” data
D/A Out
(Analog)
D/A In
(Digital)
Clock In
MCLK,LRCK,BICK
(1) (3)
DZF
(3) (1)
(2)
Normal Operation
2/fs(5)
Internal
RSTN bit
2~3/fs (6)3~4/fs (6)
Don’t care
(4)
Notes:
(1) The analog output corresponding to digital input has the group delay (GD).
(2) Analog outputs go to VCOM voltage (VDD/2).
(3) Click noi se occurs a t the edges(“↑ ↓”) of the int ernal ti ming of RSTN bit . This noise is output even if “0” data is
input.
(4) The external clocks (MCLK, BICK and LRCK) can be stopped in the reset mode (RSTN = “L”).
(5) DZF pins go to “H” when the RSTN bit becomes “0”, and go to “L” at 2/fs after RSTN bit becomes “1”.
(6) There is a delay, 3~4/fs from RSTN bit “0” to the internal RSTN bit “0”, and 2~3/fs from RSTN bit “1” to the
internal RS TN “1”.
Figure 7. Reset Sequence Example
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 16 -
Mode Control Interface
Internal registers may be written by 3-wire µP interface pins, C SN, CCLK and CDTI. The data on this interface consists
of Chip Address (2bits, C1/0; fixed to “01”), Read/Write (1bit; fixed to “1”, Write only), Register Address (MSB first,
5bits) and Control Data (MSB first, 8bits). AK4385 l atches the data on the rising edge of CCLK, so data should clocked
in on the falling edge. The writing of data becomes valid by CSN “↑”. The clock speed of CCLK is 5MHz (max).
PDN = “L” resets the registers to their default values. The internal timing circuit is reset by RSTN bit, but the registers are
not initia liz e d .
CDTI
CCLK
CSN
C1
012345678 9 10 11 12 13 14 15
D4D5D6D7A1A2A3A4R/WC0 A0 D0D1D2D3
C1-C0: Chip Address (Fixed to “01”)
R/W: RE AD/ WRITE (Fixed to “1”, Write only)
A4-A0: Register Address
D7-D0: Control Data
Figure 8. Control I/ F T iming
*AK4385 does not support the read command and chip address. C 1/0 and R /W are fixed to “011”
*When the AK4385 is in the power down mode (PDN = “L”) or the MCLK is not provided, writing into the control
register is inhibi ted.
Register Map
Addr Register Name D7 D6 D5 D4 D3 D2 D1 D0
00H Control 1 ACKS 0 0 DIF2 DIF1 DIF0 PW RSTN
01H Control 2 DZFE DZFM SLOW DFS1 DFS0 DEM1 DEM0 SMUTE
02H Control 3 0 0 0 0 0 DZFB 0 0
03H Lch ATT ATT7 ATT6 ATT5 ATT4 ATT3 ATT2 ATT1 ATT0
04H Rch ATT ATT7 ATT6 ATT5 ATT4 ATT3 ATT2 ATT1 ATT0
Notes:
For addresses from 05H to 1FH, data m ust not be written.
When PDN pin goes “L”, the registers are ini tialized to their default values.
When RSTN bit goes “0”, the only internal timing is reset and the registers are not initialized to their default
values.
All data can be written to the register even if PW or RSTN bit is “0”.
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 17 -
Register Definitions
Addr Register Name D7 D6 D5 D4 D3 D2 D1 D0
00H Control 1 ACKS 0 0 DIF2 DIF1 DIF0 PW RSTN
default 1 0 0 0 1 0 1 1
RSTN: Internal timing reset control
0: Reset. All regist ers are not initiali zed.
1: Normal Operation
When MCLK frequency or DFS changes, the AK4385 should be reset by PDN pin or RSTN bit .
PW: Power down control
0: Power down. All regist ers are not initialized.
1: Normal Operation
DIF2-0: Audio data interface formats (see Table 7)
Initial: “010”, Mode 2
ACKS: Mast er Clock Frequency Auto Setting Mode Enable
0: Disable, M a nual Setting Mode
1: Enable, A uto Setting Mode
Master clock frequency is detected autom atically at ACKS bit “1”. In this case, the setting of DFS1-0
are ignored. When this bit is “0”, DFS1-0 set the sampling speed mode.
Addr Register Name D7 D6 D5 D4 D3 D2 D1 D0
01H Control 2 DZFE DZFM SLOW DFS1 DFS0 DEM1 DEM0 SMUTE
default 0 0 0 0 0 0 1 0
SMUTE: Soft Mute Enable
0: Normal operation
1: DAC outputs soft-muted
DEM1-0: De-emphasis Response (see Table 8)
Initial: “01”, OFF
DFS1-0: Sampling speed control
00: Normal speed
01: Double speed
10: Quad speed
When changing between Normal/Doubl e Speed Mode and Quad Speed Mode, some click noise
occurs.
SLOW: Slow Roll-off Filter Enable
0: Sharp Roll-off Filter
1: Slow Roll-off Filter
DZFE: Data Zero Detect Enable
0: Disable
1: Enable
Zero detect function c an be disabl ed by DZFE bit “0”. In this case, the DZF pins of both channel s are
always “L”.
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 18 -
DZFM: Data Zero Detect Mode
0: Channel Separated Mode
1: Channel ANDed Mode
If the DZ FM bit is set to “1”, the DZF pi ns of both channels go t o “H” only when the input data at both
channels are continuously zeros for 8192 LRCK cycles.
Addr Register Name D7 D6 D5 D4 D3 D2 D1 D0
02H Control 3 0 0 0 0 0 DZFB 0 0
default 0 0 0 0 0 0 0 0
DZFB: Inverting Enable of DZF
0: DZF goes “H” at Zero Detection
1: DZF goes “L” at Zero Detecti on
Addr Register Name D7 D6 D5 D4 D3 D2 D1 D0
03H Lch ATT ATT7 ATT6 ATT5 ATT4 ATT3 ATT2 ATT1 ATT0
04H Rch ATT ATT7 ATT6 ATT5 ATT4 ATT3 ATT2 ATT1 ATT0
default 1 1 1 1 1 1 1 1
ATT = 20 log
10 (ATT_DATA / 255) [dB]
00H: Mute
SYSTEM DESIGN
Figure 9 shows the system connection diagram. An evaluation board (AKD4385) is available in order to allow an easy
study on the layout of a surrounding circuit.
MCLK
1
BICK
2
SDTI
3
LRCK
4
PDN
5
CSN
6
CCLK
7
CDTI 8
DZFL 16
DZFR 15
VDD 14
VSS 13
AOUTL+ 12
AOUTL- 11
AOUTR+ 10
AOUTR- 9
Master Clock
Micro-
controller
AK4385
fs
24bit Audio Data
Reset & Power down
64fs
10u
0.1u +
Lch
LPF
Rch
LPF Rch Out
Lch Out
Analog Ground Digital Ground
Lch
MUTE
Rch
MUTE
A
nalog
Supply 5V
Figure 9. Typical Connection Diagram
Notes:
- LRCK = fs, BI CK = 64fs.
- When AOUT drives some capacitive load, some resist or should be added in series between AOUT and
capacitive load.
- All input pins except pull-down/pull-up pins should not be left floating.
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 19 -
1. Grounding and Pow er Supply Decoupling
VDD and VSS are supplied from analog supply and should be separated from system di gital supply. Decoupling
capacitor, especially 0.1µF cerami c capacitor for high frequency shoul d be placed as near to VDD as possible. The
differential Voltage between VDD and VSS pins set the ana log output range.
2. Analog Outputs
The analog outputs are full-differential outputs and 0.55 x VDD Vpp (typ) centered around the internal common voltage
(about AVDD/2). The differential outputs are summed externally, VAOUT=(AOUT+)-(AOUT-) between AOUT+ and
AOUT-. If the summing gain is 1, the out put range is 5.5Vpp (typ @VREFH=5V). The bias voltage of the exte rnal
summ ing circui t is suppli ed externall y. The input data form at is 2’s com pleme nt. The output vol tage (VAOUT) i s a positi ve
full scale for 7FFFFF (@24bit) and a negat ive full scale for 800000H (@24bit). The ideal VAOUT is 0V for 000000H
(@24bit).
The internal switched-capacitor filter and external low pass filter attenuate the noise generated by the delta-sigma
modulator beyond the audio passband. DC offset on AOUT+/- is eliminated without AC coupling since the analog
outputs are di fferential. Figure 10 and 11 show the example of external op-a mp circuit summing the differential outputs.
4.7k 4.7k
R1
4.7k R1
4.7k 470p
Vop
470p
Vop
1k
1k47u
0.1u
BIAS
AOUT-
AOUT+
3300p
When R1=200Ω
When R1=180Ω
fc=93.2kHz, Q=0.712, g=-0.1dB at 40kHz
fc=98.2kHz, Q=0.681, g=-0.2dB at 40kHz
Analog
Out
Figure 10. External 2nd order LPF Circuit Example (using op-amp with single power supply)
4.7k 4.7k
R1
4.7k R1
4.7k 470p
+Vop
470p
-Vop
AOUT-
AOUT+
3300p
When R1=200Ω
When R1=180Ω
fc=93.2kHz, Q=0.712, g=-0.1dB at 40kHz
fc=98.2kHz, Q=0.681, g=-0.2dB at 40kHz
Analog
Out
Figure 11. External 2nd order LPF Circuit Example (using op-amp with dual power supplies)
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 20 -
PACKAGE
0-10°
Detail A
Seating Plane 0.10
0.17
±
0.05
0.22±0.1 0.65
*5.0±0.1 1.05±0.05
A
18
916
16
p
in TSSOP
(
Unit: mm
)
*4.4±0.1
6.4±0.2
0.5±0.2
0.1±0.1
NOTE: Dimension "*" does not include mold flash.
0.13 M
Package & Lead frame material
Package molding compound: Epoxy
Lead frame material: Cu
Lead frame surface treatment: Solder(Pb free) plate
ASAHI KASEI [AK4385]
MS0246-E-00 2003/07
- 21 -
MARKING
AKM
4385VT
XXYYY
1) Pin #1 indication
2) Date Code : XXYYY (5 digit s)
XX: Lot#
YYY: Date Code
3) Marketing Code : 4385VT
4) Asahi Kasei Logo
IMPORTANT NOTICE
• These produc ts and their s pecifications are subject t o change without notic e. Before cons idering
any use or applic ation, consult the Asahi K asei Microsystems Co., Lt d. (AKM) sales offi ce or
authorized di stributor c oncerning their c urrent status .
• AKM as sumes no liability f or infringement of any patent, intellec tual property, or ot her right in the
applicat ion or use of any informat ion contained herein.
• Any export of these products, or devices or systems c ontaining them, m ay require an export license
or other official approval under the law and regulations of the country of export pertaining to customs
and tarif fs, curre ncy exchange, or st rategic mat erials.
• AKM produc ts are neither int ended nor authorized f or use as crit ical component s in any safet y, life
support , or other hazard related dev ice or syst em, and AKM as sumes no responsib ility relating t o
any such use, except with t he express written c onsent of t he Representativ e Director of A KM. As
used here:
(a) A hazard related device or system is one designed or intended for life support or maintenance of
safet y or for applications in medicine, aerosp ace, nuclear energy, or ot her fields, in which it s
failure t o func tion or perform may reaso nably be expec t ed to res ult i n lo ss of life or in si gnif icant
injury or damage to pers on or property.
(b) A cri tical c omponent is one whose fail ure to func tion or perf orm may reas onably be ex pected t o
result, whether directly or indir ectly, in the l oss of the saf ety or effectiv eness of the dev ice or
syst em containing it , and which must theref ore meet very high s tandards of perform ance and
reliability.
• It is the respons ibility of the buyer or dis tributor of an AKM product who dist ributes , dispo ses of , or
otherwise plac es the product with a t hird party to notif y that party in adv ance of the above content
and conditio ns, and t he buyer or dist ribut or agrees to as sume any and all res ponsi bilit y and liabi lity
for and hold AK M harmless f rom any and all claims arising from the us e of said product in the
absence of such notif ication.
