AKM AKD4370

ASAHI KASEI
[AK4370]
AK4370
24-Bit 2ch DAC with HP-AMP & Output Mixer
GENERAL DESCRIPTION
The AK4370 is a 24-bit DAC with headphone amplifier. The AK4370 features an analog mixing circuit that
allows easy interfacing in mobile phone and portable communication designs. The integrated headphone
amplifier features “pop-noise free” power-on/off, a mute control, and it delivers 40mW of power into 16Ω.
The AK4370 is packaged in a 24-pin QFN (4mm×4mm) package, ideal for portable applications.
FEATURE
† Multi-bit ΔΣ DAC
† Sampling Rate
- 8kHz ∼ 48kHz
† On chip perfect filtering 8 times FIR interpolator
- Passband: 20kHz
- Passband Ripple: ±0.02dB
- Stopband Attenuation: 54dB
† Digital De-emphasis Filter: 32kHz, 44.1kHz and 48kHz
† System Clock
- 256fs/384fs/512fs/768fs/1024fs
- Input Level: AC Couple Input Available
† Audio I/F Format: MSB First, 2’s Complement
- I2S, 24bit MSB justified, 24bit/20bit/16bit LSB justified
- Master/Slave Mode
† Digital Mixing: LR, LL, RR, (L+R)/2
† Bass Boost Function
† Digital ATT
† Analog Mixing Circuit: 4 Inputs (Single-ended or Full-differential)
† Stereo Lineout
- S/N: [email protected]
- Output Volume: +6 to –24dB (or 0 to –30dB), 2dB step
† Headphone Amplifier
- Output Power: 40mW x 2ch @16Ω, 3.3V
- S/N: [email protected]
- Pop Noise Free at Power-ON/OFF and Mute
- Output Volume: 0 ~ –63dB & +12/+6/0 dB Gain
1.5dB step (0 ~ –30dB), 3dB step (–30 ~ –63dB)
† μP Interface: 3-wire/I2C
† Power Supply: 1.6V ∼ 3.6V
† Power Supply Current: 3.8mA @1.8V (6.8mW, DAC+HP, No output)
† Ta: −30 ∼ 85°C
† Small Package: 24pin QFN (4mm x 4mm, 0.5mm pitch)
† Register Compatible with AK4368
MS0595-E-00
2007/03
-1-
ASAHI KASEI
[AK4370]
■ Block Diagram
LIN1/IN− LIN2
MCKI
BICK
LRCK
SDATA
Audio
Interface
VSS1
Clock
Divider
VCOM
VCOM
DVDD
VSS2
AVDD
DAC
Digital
Volume
Deemphasis
Bass
Boost
Digital
Filter
LOUT
(Lch)
ROUT
DAC
(Rch)
PDN
I2C
HDP
Amp
MUTE
HPL
HDP
Amp
MUTE
HPR
CAD0/CSN
SCL/CCLK
Serial I/F
SDA/CDTI
RIN1/IN+ RIN2
HVDD
MUTET
Figure 1. Block Diagram
MS0595-E-00
2007/03
-2-
ASAHI KASEI
[AK4370]
■ Ordering Information
AK4370VN
AKD4370
−30 ∼ +85°C
24pin QFN (0.5mm pitch)
Evaluation board for AK4370
VSS1
HVDD
AVDD
VCOM
ROUT
LOUT
18
17
16
15
14
13
■ Pin Layout
PDN
LIN2
22
Top View
9
CSN/CAD0
RIN1/IN+
23
8
CCLK/SCL
LIN1/IN−
24
7
CDTI/SDA
6
10
VSS2
AK4370VN
5
21
DVDD
RIN2
4
I2C
MCKI
11
3
20
LRCK
HPL
2
MUTET
BICK
12
1
19
SDATA
HPR
MS0595-E-00
2007/03
-3-
ASAHI KASEI
[AK4370]
■ Comparison with AK4368
1 Function
Function
AK4368
Analog Mixing
1-Stereo + 1-Mono
Single-ended Input
MCKI at EXT Mode
256fs/512fs/1024fs,
12.288MHz(max)
HP-Amp Output Volume
No
HP-Amp Hi-Z Setting
PLL
3D Enhancement
ALC
Package
No
Yes
Yes
Yes
41BGA (4mm x 4mm)
2
AK4370
2-Stereo
Single-ended Input
or Full-differential Input
256fs/384fs/512fs/768fs/1024fs,
24.576MHz(max)
0 to –63dB & +12/+6/0dB
1.5dB step (0 to –30dB)
3dB step (–30 to –63dB)
Yes
No
No
No
24QFN (4mm x 4mm)
Register (difference from AK4368)
Addr
00H
01H
02H
03H
04H
05H
06H
07H
08H
09H
0AH
0BH
0CH
0DH
0EH
0FH
10H
11H
12H
13H
Register Name
Power Management
Clock Control 0
Clock Control 1
Mode Control 0
Mode Control 1
DAC Lch ATT
DAC Rch ATT
Headphone Out Select 0
Lineout Select 0
Lineout ATT
Reserved
Reserved
Reserved
Headphone Out Select 1
Headphone ATT
Lineout Select 1
Mono Mixing
Differential Select
Reserved
Reserved
D7
0
FS3
0
0
ATS
ATTL7
ATTR7
HPG1
0
0
REF7
0
0
0
0
0
0
0
0
0
D6
D5
D4
D3
PMPLL
PMLO
MUTEN PMHPR
FS2
FS1
FS0
PLL3
0
M/S
MCKAC
BF
MONO1 MONO0
BCKP
LRP
DATTC LMUTE SMUTE
BST1
ATTL6
ATTL5
ATTL4
ATTL3
ATTR6
ATTR5
ATTR4
ATTR3
HPG0
LIN2HR LIN2HL RIN1HR
LOG
LIN2R
LIN2L
RIN1R
0
0
0
ATTS3
REF6
REF5
REF4
REF3
0
ALC
ROTM1 ROTM0
0
0
0
DP1
0
0
0
RIN2HR
HPZ
HMUTE ATTH4
ATTH3
0
0
0
RIN2R
0
0
0
L2M
0
0
0
0
0
0
0
0
0
0
1
0
These bits are added in the AK4370
These bits are deleted in the AK4370
MS0595-E-00
D2
PMHPL
PLL2
PS0
DIF2
BST0
ATTL2
ATTR2
LIN1HL
LIN1L
ATTS2
REF2
LMAT1
DP0
RIN2HL
ATTH2
RIN2L
L2HM
0
0
0
D1
PMDAC
PLL1
PS1
DIF1
DEM1
ATTL1
ATTR1
DARHR
DARR
ATTS1
REF1
LMAT0
3D1
LIN1HR
ATTH1
LIN1R
L1M
LDIFH
0
0
D0
PMVCM
PLL0
MCKO
DIF0
DEM0
ATTL0
ATTR0
DALHL
DALL
ATTS0
REF0
RATT
3D0
RIN1HL
ATTH0
RIN1L
L1HM
LDIF
0
0
2007/03
-4-
ASAHI KASEI
[AK4370]
PIN/FUNCTION
No.
1
2
3
4
5
6
7
8
9
Pin Name
SDATA
BICK
LRCK
MCKI
DVDD
VSS2
SDA
CDTI
SCL
CCLK
CAD0
CSN
I/O
I
I/O
I/O
I
I/O
I
I
I
I
I
10
PDN
I
11
I2C
I
12
MUTET
O
13
14
LOUT
ROUT
O
O
15
VCOM
O
16
17
18
19
20
21
22
AVDD
HVDD
VSS1
HPR
HPL
RIN2
LIN2
RIN1
IN+
LIN1
IN−
O
O
I
I
I
I
I
I
23
24
Function
Audio Serial Data Input Pin
Audio Serial Data Clock Pin
Input / Output Channel Clock Pin
External Master Clock Input Pin
Digital Power Supply Pin, 1.6 ∼ 3.6V
Ground 2 Pin. Connected to VSS1.
Control Data Input/Output Pin (I2C mode : I2C pin = “H”)
Control Data Input Pin (3-wire serial mode : I2C pin = “L”)
Control Data Clock Pin (I2C mode : I2C pin = “H”)
Control Data Clock Pin (3-wire serial mode : I2C pin = “L”)
Chip Address 0 Select Pin (I2C mode : I2C pin = “H”)
Chip Select Pin (3-wire serial mode : I2C pin = “L”)
Power-down & Reset
When “L”, the AK4370 is in power-down mode and is held in reset.
The AK4370 should always be reset upon power-up.
Control Mode Select Pin
“H”: I2C Bus, “L”: 3-wire Serial
Mute Time Constant Control pin
Connected to VSS1 pin with a capacitor for mute time constant.
Lch Stereo Line Output Pin
Rch Stereo Line Output Pin
Common Voltage Output Pin
Normally connected to VSS1 pin with a 2.2μF electrolytic capacitor.
Analog Power Supply Pin, 1.6 ∼ 3.6V
Power Supply Pin for Headphone Amp, 1.6 ∼ 3.6V
Ground 1 Pin
Rch Headphone Amp Output
Lch Headphone Amp Output
Rch Analog Input 2 Pin
Lch Analog Input 2 Pin
Rch Analog Input 1 Pin (LDIF bit =“0” : Single-ended Input)
Positive Line Input Pin (LDIF bit =“1” : Full-differential Input)
Rch Analog Input 1 Pin (LDIF bit =“0” : Single-ended Input)
Negative Line Input Pin (LDIF bit =“1” : Full-differential Input)
Note 1. All digital input pins (I2C, SDA/CDTI, SCL/CCLK, CAD0/CSN, SDATA, LRCK, BICK, MCKI, PDN) must not
be left floating. MCKI pin can be left floating only when PDN pin = “L”.
MS0595-E-00
2007/03
-5-
ASAHI KASEI
[AK4370]
■ Handling of Unused Pin
The unused I/O pins should be processed appropriately as below.
Classification
Analog
Digital
Pin Name
LOUT, ROUT, MUTET, HPL, HPR, LIN2, RIN2,
RIN1/IN+, LIN1/IN−
MCKI
Setting
These pins should be open.
This pin should be connected to VSS2.
ABSOLUATE MAXIMUM RATING
(VSS1, VSS2=0V; Note 2, Note 3)
Parameter
Symbol
min
max
Units
Power Supplies Analog
AVDD
4.6
V
−0.3
Digital
DVDD
4.6
V
−0.3
HP-Amp
HVDD
4.6
V
−0.3
Input Current (any pins except for supplies)
IIN
mA
±10
Analog Input Voltage (Note 4)
VINA
(AVDD+0.3) or 4.6
V
−0.3
Digital Input Voltage (Note 5)
VIND
(DVDD+0.3) or 4.6
V
−0.3
Ambient Temperature
Ta
85
−30
°C
Storage Temperature
Tstg
150
−65
°C
Note 2. All voltages with respect to ground.
Note 3. VSS1 and VSS2 must be connected to the same analog ground plane.
Note 4. LIN1/IN−, RIN1/IN+, LIN2 and RIN2 pins. Max is smaller value between (AVDD+0.3)V and 4.6V.
Note 5. SDA/CDTI, SCL/CCLK, CAD0/CSN, SDATA, LRCK, BICK, MCKI, PDN and I2C pins. Max is smaller value
between (DVDD+0.3)V and 4.6V.
WARNING: Operation at or beyond these limits may result in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
RECOMMEND OPERATING CONDITIONS
(VSS1, VSS2=0V; Note 2)
Parameter
Symbol
min
typ
max
Units
Power Supplies Analog
AVDD
1.6
2.4
3.6
V
(Note 6)
Digital (Note 7)
DVDD
1.6
2.4
(AVDD+0.2) or 3.6
V
HP-Amp
HVDD
1.6
2.4
3.6
V
Difference
0
+0.3
V
AVDD−HVDD
−0.3
Note 2. All voltages with respect to ground.
Note 6. When AVDD and DVDD are supplied separately, AVDD should be powered-up after DVDD rises up to 1.6V or
more. When the AK4370 is powered-down, DVDD should be powered-down at the same time or later than
AVDD. When AVDD and HVDD are supplied separately, AVDD should be powered-up at the same time or
earlier than HVDD. When the AK4370 is powered-down, AVDD should be powered-down at the same time or
later than HVDD.
Note 7. Max is smaller value between (AVDD+0.2)V and 3.6V.
* AKM assumes no responsibility for usage beyond the conditions in this datasheet.
MS0595-E-00
2007/03
-6-
ASAHI KASEI
[AK4370]
ANALOG CHARACTERISTICS
(Ta=25°C; AVDD=DVDD=HVDD=2.4V, VSS1=VSS2=0V; fs=44.1kHz; BOOST OFF; Slave Mode; Signal Frequency
=1kHz; Measurement band width=20Hz ∼ 20kHz; Headphone-Amp: Load impedance is a serial connection with RL
=16Ω and CL=220μF. (Refer to Figure 38; unless otherwise specified)
Parameter
min
typ
max
Units
24
bit
DAC Resolution
Headphone-Amp: (HPL/HPR pins) (Note 8)
Analog Output Characteristics
THD+N
dB
−3dBFS Output, 2.4V, [email protected]
−50
−40
dB
0dBFS Output, 3.3V, [email protected]
−20
82
90
dB
D-Range
−60dBFS Output, A-weighted, 2.4V
92
dB
−60dBFS Output, A-weighted, 3.3V
S/N
A-weighted, 2.4V
82
90
dB
A-weighted, 3.3V
92
dB
Interchannel Isolation
60
80
dB
DC Accuracy
Interchannel Gain Mismatch
0.3
0.8
dB
Gain Drift
200
ppm/°C
Load Resistance (Note 9)
16
Ω
Load Capacitance
300
pF
1.04
1.16
1.28
Vpp
Output Voltage −3dBFS Output (Note 10)
0dBFS Output, 3.3V,
0.8
Vrms
[email protected]
Output Volume: (HPL/HPR pins)
Step Size
0.1
1.5
2.9
dB
0 ∼ –30dB
(HPG1-0 bits = “00”)
0.1
3
5.9
dB
–30 ∼ –63dB
Gain Control Range
Max (ATT4-0 bits = “00H”)
0
dB
(HPG1-0 bits = “00”)
Min (ATT4-0 bits = “1FH”)
dB
−63
Stereo Line Output: (LOUT/ROUT pins, RL=10kΩ) (Note 11)
Analog Output Characteristics:
THD+N (0dBFS Output)
dB
−60
−50
S/N
A-weighted, 2.4V
80
87
dB
A-weighted, 3.3V
90
dB
DC Accuracy
Gain Drift
200
ppm/°C
Load Resistance (Note 9)
10
kΩ
Load Capacitance
25
pF
Output Voltage (0dBFS Output) (Note 12)
1.32
1.47
1.61
Vpp
Output Volume: (LOUT/ROUT pins)
Step Size
1
2
3
dB
Gain Control Range
Max (ATTS3-0 bits = “FH”)
0
dB
(LOG1-0 bit = “0”)
Min (ATTS3-0 bits = “0H”)
dB
−30
Note 8. DALHL=DARHR bits = “1”
LIN1HL=RIN1HL=LIN2HL=RIN2HL=LIN1HR=RIN1HR=LIN2HR=RIN2HR bits = “0”.
Note 9. AC load.
Note 10. Output voltage is proportional to AVDD voltage. Vout = 0.48 x AVDD(typ)@−3dBFS.
Note 11. DALL=DARR bits = “1”
LIN1L=RIN1L=LIN2L=RIN2L=LIN1R=RIN1R=LIN2R=RIN2R bits = “0”
Note 12. Output voltage is proportional to AVDD voltage. Vout = 0.61 x AVDD(typ)@0dBFS.
MS0595-E-00
2007/03
-7-
ASAHI KASEI
[AK4370]
Parameter
LINEIN: (LIN1/RIN1/LIN2/RIN2 pins)
Analog Input Characteristics
Input Resistance (Refer to Figure 21, Figure 22)
LIN1 pin
LIN1HL=LIN1HR=LIN1L=LIN1R bits = “1”
LIN1HL bit = “1”, LIN1HR=LIN1L=LIN1R bits = “0”
LIN1HR bit = “1”, LIN1HL=LIN1L=LIN1R bits = “0”
LIN1L bit = “1”, LIN1HL=LIN1HR=LIN1R bits = “0”
LIN1R bit = “1”, LIN1HL=LIN1HR=LIN1L bits = “0”
RIN1 pin
RIN1HL=RIN1HR=RIN1L=RIN1R bits = “1”
RIN1HL bit = “1”, RIN1HR=RIN1L=RIN1R bits = “0”
RIN1HR bit = “1”, RIN1HL=RIN1L=RIN1R bits = “0”
RIN1L bit = “1”, RIN1HL=RIN1HR=RIN1R bits = “0”
RIN1R bit = “1”, RIN1HL=RIN1HR=RIN1L bits = “0”
LIN2 pin
LIN2HL=LIN2HR=LIN2L=LIN2R= bits = “1”
LIN2HL bit = “1”, LIN2HR=LIN2L=LIN2R bits = “0”
LIN2HR bit = “1”, LIN2HL=LIN2L=LIN2R bits = “0”
LIN2L bit = “1”, LIN2HL=LIN2HR=LIN2R bits = “0”
LIN2R bit = “1”, LIN2HL=LIN2HR=LIN2L bits = “0”
RIN2 pin
RIN2HL=RIN2HR=RIN2L=RIN2R bits = “1”
RIN2HL bit = “1”, RIN2HR=RIN2L=RIN2R bits = “0”
RIN2HR bit = “1”, RIN2HL=RIN2L=RIN2R bits = “0”
RIN2L bit = “1”, RIN2HL=RIN2HR=RIN2R bits = “0”
RIN2R bit = “1”, RIN2HL=RIN2HR=RIN2L bits = “0”
Gain
LIN1/LIN2/RIN1/RIN2 Æ LOUT/ROUT
LIN1/LIN2/RIN1/RIN2 Æ HPL/HPR
Power Supplies
Power Supply Current
Normal Operation (PDN pin = “H”) (Note 13)
AVDD+DVDD
HVDD
Power-Down Mode (PDN pin = “L”) (Note 14)
min
typ
max
Units
14
-
25
100
100
100
100
-
kΩ
kΩ
kΩ
kΩ
kΩ
14
-
25
100
100
100
100
-
kΩ
kΩ
kΩ
kΩ
kΩ
14
-
25
100
100
100
100
-
kΩ
kΩ
kΩ
kΩ
kΩ
14
-
25
100
100
100
100
-
kΩ
kΩ
kΩ
kΩ
kΩ
−1
−0.05
0
+0.95
+1
+1.95
dB
dB
-
3.8
1.2
1
5.5
2.5
100
mA
mA
μA
Note 13. PMDAC=PMHPL=PMHPR=PMLO bits = “1”, MUTEN bit = “1”, HP-Amp no output.
PMDAC=PMHPL=PMHPR= “1”, PMLO bit= “0”, AVDD+DVDD+HVDD=4.0mA (typ) @2.4V, 3.8mA (typ)
@1.8V.
Note 14. All digital input pins are fixed to VSS2.
MS0595-E-00
2007/03
-8-
ASAHI KASEI
[AK4370]
FILTER CHARACTERISTICS
(Ta=25°C; AVDD, DVDD, HVDD=1.6 ∼ 3.6V; fs=44.1kHz; De-emphasis = “OFF”)
Parameter
Symbol
min
typ
DAC Digital Filter: (Note 15)
Passband (Note 16)
PB
0
−0.05dB
22.05
−6.0dB
Stopband (Note 16)
SB
24.1
Passband Ripple
PR
Stopband Attenuation
SA
54
Group Delay (Note 17)
GD
22
Group Delay Distortion
0
ΔGD
DAC Digital Filter + Analog Filter: (Note 15, Note 18)
Frequency Response
FR
0 ∼ 20.0kHz
±0.5
Analog Filter: (Note 19)
Frequency Response
FR
0 ∼ 20.0kHz
±1.0
BOOST Filter: (Note 18, Note 20)
Frequency Response
20Hz
FR
5.76
MIN
100Hz
2.92
1kHz
0.02
20Hz
FR
10.80
MID
100Hz
6.84
1kHz
0.13
20Hz
FR
16.06
MAX 100Hz
10.54
1kHz
0.37
max
Units
20.0
±0.02
-
kHz
kHz
kHz
dB
dB
1/fs
µs
-
dB
-
dB
-
dB
dB
dB
dB
dB
dB
dB
dB
dB
Note 15. BOOST OFF (BST1-0 bit = “00”)
Note 16. The passband and stopband frequencies scale with fs (system sampling rate).
For example, PB=0.4535fs(@−0.05dB). SB=0.546fs(@−54dB).
Note 17. This time is from setting the 24-bit data of both channels from the input register to the output of analog signal.
Note 18. DAC Æ HPL, HPR, LOUT, ROUT
Note 19. LIN1/LIN2/RIN1/RIN2 Æ HPL/HPR/LOUT/ROUT
Note 20. These frequency responses scale with fs. If high-level signal is input, the output clips at low frequency.
Boost Filter (fs=44.1kHz)
20
MAX
15
Gain [dB]
MID
10
MIN
5
0
-5
10
100
1000
10000
Frequency [Hz]
Figure 2. Boost Frequency (fs=44.1kHz)
MS0595-E-00
2007/03
-9-
ASAHI KASEI
[AK4370]
DC CHARACTERISTICS
(Ta=25°C; AVDD, DVDD, HVDD=1.6 ∼ 3.6V)
Parameter
Symbol
min
High-Level Input Voltage
2.2V≤DVDD≤3.6V
VIH
70%DVDD
1.6V≤DVDD<2.2V
VIH
80%DVDD
Low-Level Input Voltage
2.2V≤DVDD≤3.6V
VIL
1.6V≤DVDD<2.2V
VIL
Input Voltage at AC Coupling (Note 21)
VAC
0.4
High-Level Output Voltage
VOH
(Iout=−200μA)
DVDD−0.2
Low-Level Output Voltage
VOL
(Except SDA pin: Iout=200μA)
VOL
(SDA pin, 2.0V≤DVDD≤3.6V: Iout=3mA)
VOL
(SDA pin, 1.6V≤DVDD<2.0V: Iout=3mA)
Input Leakage Current
Iin
-
typ
-
max
30%DVDD
20%DVDD
-
Units
V
V
V
V
Vpp
V
-
0.2
0.4
20%DVDD
±10
V
V
V
μA
Note 21. MCKI is connected to a capacitor. (Refer to Figure 38)
MS0595-E-00
2007/03
- 10 -
ASAHI KASEI
[AK4370]
SWITCHING CHARACTERISTICS
(Ta=25°C; AVDD, DVDD, HVDD=1.6 ∼ 3.6V; CL = 20pF; unless otherwise specified)
Parameter
Symbol
min
Master Clock Input Timing
Frequency
fCLK
2.048
Pulse Width Low (Note 22)
tCLKL
0.4/fCLK
Pulse Width High (Note 22)
tCLKH
0.4/fCLK
AC Pulse Width (Note 23)
tACW
20.3
LRCK Timing
Frequency
fs
8
Duty Cycle: Slave Mode
Duty
45
Master Mode
Duty
Serial Interface Timing (Note 24)
Slave Mode (M/S bit = “0”):
BICK Period (Note 25)
tBCK
312.5 or 1/(64fs)
BICK Pulse Width Low
tBCKL
100
Pulse Width High
tBCKH
100
tLRB
50
LRCK Edge to BICK “↑” (Note 26)
tBLR
50
BICK “↑” to LRCK Edge (Note 26)
SDATA Hold Time
tSDH
50
SDATA Setup Time
tSDS
50
Master Mode (M/S bit = “1”):
BICK Frequency (BF bit = “1”)
fBCK
(BF bit = “0”)
fBCK
BICK Duty
dBCK
tMBLR
BICK “↓” to LRCK
−50
SDATA Hold Time
tSDH
50
SDATA Setup Time
tSDS
50
Control Interface Timing (3-wire Serial mode)
CCLK Period
tCCK
200
CCLK Pulse Width Low
tCCKL
80
Pulse Width High
tCCKH
80
CDTI Setup Time
tCDS
40
CDTI Hold Time
tCDH
40
CSN “H” Time
tCSW
150
tCSS
50
CSN “↑” to CCLK “↑”
tCSH
50
CCLK “↑” to CSN “↑”
typ
max
Units
-
24.576
-
MHz
ns
ns
ns
44.1
50
48
55
-
kHz
%
%
-
1/(32fs)
-
ns
ns
ns
ns
ns
ns
ns
64fs
32fs
50
-
50
-
Hz
Hz
%
ns
ns
ns
-
-
ns
ns
ns
ns
ns
ns
ns
ns
Note 22. Except AC coupling.
Note 23. Pulse width to ground level when MCKI is connected to a capacitor in series and a resistor is connected to
ground. (Refer to Figure 3.)
Note 24. Refer to “Serial Data Interface”.
Note 25. Min is longer value between 312.5ns or 1/(64fs) except for PLL Mode, PLL4-0 bits = “EH”, “FH”.
Note 26. BICK rising edge must not occur at the same time as LRCK edge.
MS0595-E-00
2007/03
- 11 -
ASAHI KASEI
Parameter
Control Interface Timing (I2C Bus mode): (Note 27)
SCL Clock Frequency
Bus Free Time Between Transmissions
Start Condition Hold Time (prior to first clock pulse)
Clock Low Time
Clock High Time
Setup Time for Repeated Start Condition
SDA Hold Time from SCL Falling (Note 28)
SDA Setup Time from SCL Rising
Rise Time of Both SDA and SCL Lines
Fall Time of Both SDA and SCL Lines
Setup Time for Stop Condition
Capacitive Load on Bus
Pulse Width of Spike Noise Suppressed by Input Filter
Power-down & Reset Timing
PDN Pulse Width (Note 29)
[AK4370]
Symbol
min
typ
max
Units
fSCL
tBUF
tHD:STA
tLOW
tHIGH
tSU:STA
tHD:DAT
tSU:DAT
tR
tF
tSU:STO
Cb
tSP
1.3
0.6
1.3
0.6
0.6
0
0.1
0.6
0
-
400
0.3
0.3
400
50
kHz
μs
μs
μs
μs
μs
μs
μs
μs
μs
μs
pF
ns
tPD
150
-
-
ns
Note 27. I2C is a registered trademark of Philips Semiconductors.
Note 28. Data must be held long enough to bridge the 300ns-transition time of SCL.
Note 29. The AK4370 can be reset by bringing PDN pin = “L” to “H” only upon power up.
MS0595-E-00
2007/03
- 12 -
ASAHI KASEI
[AK4370]
■ Timing Diagram
1/fCLK
tACW
1000pF
tACW
Measurement
Point
MCKI Input
VAC
100kΩ
VSS2
VSS2
Figure 3. MCKI AC Coupling Timing
1/fCLK
VIH
MCKI
VIL
tCLKH
tCLKL
1/fs
VIH
LRCK
VIL
tBCK
VIH
BICK
VIL
tBCKH
tBCKL
Figure 4. Clock Timing
MS0595-E-00
2007/03
- 13 -
ASAHI KASEI
[AK4370]
VIH
LRCK
VIL
tBLR
tLRB
VIH
BICK
VIL
tSDH
tSDS
VIH
SDATA
VIL
Figure 5. Serial Interface Timing (Slave Mode)
50%DVDD
LRCK
tMBLR
BICK
50%DVDD
tSDH
tSDS
VIH
SDATA
VIL
Figure 6. Serial Interface Timing (Master mode)
MS0595-E-00
2007/03
- 14 -
ASAHI KASEI
[AK4370]
VIH
CSN
VIL
tCSS
tCCKL tCCKH
VIH
CCLK
VIL
tCDS
CDTI
C1
tCDH
C0
R/W
VIH
A4
VIL
Figure 7. WRITE Command Input Timing
tCSW
VIH
CSN
VIL
tCSH
VIH
CCLK
VIL
D3
CDTI
D2
D1
VIH
D0
VIL
Figure 8. WRITE Data Input Timing
VIH
SDA
VIL
tLOW
tBUF
tR
tHIGH
tF
tSP
VIH
SCL
VIL
tHD:STA
Stop
Start
tHD:DAT
tSU:DAT
tSU:STA
tSU:STO
Start
Stop
Figure 9. I2C Bus Mode Timing
tPD
PDN
VIL
Figure 10. Power-down & Reset Timing
MS0595-E-00
2007/03
- 15 -
ASAHI KASEI
[AK4370]
OPERATION OVERVIEW
■ System Clock
The AK4370 supports both master and slave modes to interface with external devices. (See Table 1).
The M/S bit selects either master or slave mode. M/S bit = “1” selects master mode and “0” selects slave mode. When the
AK4370 is power-down mode (PDN pin = “L”) and exits reset state, the AK4370 is slave mode. After exiting reset state,
the AK4370 goes to master mode by changing M/S bit = “1”.
When the AK4370 is used by master mode, LRCK and BICK pins are a floating state until M/S bit becomes “1”. LRCK
and BICK pins of the AK4370 should be pulled-down or pulled-up by the resistor (about 100kΩ) externally to avoid the
floating state.
M/S bit
Mode
1
Master Mode
0
Slave Mode
MCKI pin
BICK pin
LRCK pin
Output
Output
Selected by FS3-0 bits
(Selected by BF bit)
(1fs)
Input
Input
Selected by FS3-0 bits
(1fs)
(32fs ∼ 64fs)
Table 1. Clock Mode Setting (x: Don’t care)
Figure
Figure 11
Figure 12
default
The frequency of master clock inputted to the MCKI pin can be selected FS3-0 bits. (Refer to Table 2)
If the sampling frequency is changed during normal operation of the DAC (PMDAC bit = “1”), the change should occur
after the input is muted by SMUTE bit = “1”, or the input is set to “0” data.
LRCK and BICK are output from the AK4370 in master mode (Figure 11). The clock input to the MCKI pin should
always be present whenever the DAC is in normal operation (PMDAC bit = “1”). If these clocks are not provided, the
AK4370 may draw excessive current and will not operate properly because it utilizes these clocks for internal dynamic
refresh of registers. If the external clocks are not present, the DAC should be placed in power-down mode (PMDAC bit =
“0”).
AK4370
DSP or μP
MCKI
BICK
LRCK
256fs, 384fs, 512fs,
768fs or 1024fs
32fs, 64fs
1fs
MCLK
BCLK
LRCK
SDTO
SDATA
Figure 11. Master Mode
MS0595-E-00
2007/03
- 16 -
ASAHI KASEI
[AK4370]
The external clocks required to operate the AK4370 in slave mode are MCKI, LRCK and BICK (Figure 12). The master
clock (MCKI) should be synchronized with the sampling clock (LRCK). The phase between these clocks does not matter.
All external clocks (MCKI, BICK and LRCK) should always be present whenever the DAC is in normal operation mode
(PMDAC bit = “1”). If these clocks are not provided, the AK4370 may draw excessive current and will not operate
properly, because it utilizes these clocks for internal dynamic refresh of registers. If the external clocks are not present, the
DAC should be placed in power-down mode (PMDAC bit = “0”).
AK4370
DSP or μP
MCKI
BICK
LRCK
256fs, 384fs, 512fs,
768fs or 1024fs
32fs ~ 64fs
1fs
MCLK
BCLK
LRCK
SDTO
SDATA
Figure 12. Slave Mode
Mode
0
1
2
4
5
6
8
9
10
12
13
Others
FS3
0
0
0
0
0
0
1
1
1
1
1
MCKI pin
BICK pin
LRCK pin
FS2
FS1
FS0
fs
MCKI
0
0
0
256fs
8kHz ∼ 48kHz
0
0
1
512fs
8kHz ∼ 48kHz
0
1
0
1024fs
8kHz ∼ 24kHz
1
0
0
256fs
8kHz ∼ 48kHz
1
0
1
512fs
8kHz ∼ 48kHz
1
1
0
1024fs
8kHz ∼ 24kHz
0
0
0
256fs
8kHz ∼ 48kHz
0
0
1
512fs
8kHz ∼ 48kHz
0
1
0
1024fs
8kHz ∼ 24kHz
1
0
0
384fs
8kHz ∼ 48kHz
1
0
1
768fs
8kHz ∼ 24kHz
Others
N/A
N/A
Table 2. Relationship between Sampling Frequency and MCKI Frequency
Default
Master Mode (M/S bit = “1”)
Power Up (PMDAC bit = “1”)
Power Down (PMDAC bit = “0”)
Refer to Table 2
Input or fixed to “L” or “H” externally
BF bit = “1”: 64fs output
“L”
BF bit = “0”: 32fs output
Output
“L”
Table 3. Clock Operation in Master mode
MS0595-E-00
2007/03
- 17 -
ASAHI KASEI
[AK4370]
MCKI pin
BICK pin
LRCK pin
Slave Mode (M/S bit = “0”)
Power Up (PMDAC bit = “1”)
Power Down (PMDAC bit = “0”)
Refer to Table 2
Input or fixed to “L” or “H” externally
Input
Fixed to “L” or “H” externally
Input
Fixed to “L” or “H” externally
Table 4. Clock Operation in Slave mode
For low sampling rates, DR and S/N degrade because of the out-of-band noise. DR and S/N are improved by using higher
frequency for MCKI. Table 5 shows DR and S/N when the DAC output is to the HP-amp.
DR, S/N (BW=20kHz, A-weight)
fs=8kHz
fs=16kHz
256fs/384fs/512fs
56dB
75dB
768fs/1024fs
75dB
90dB
Table 5. Relationship between MCKI frequency and DR (and S/N) of HP-amp (2.4V)
MCKI
MS0595-E-00
2007/03
- 18 -
ASAHI KASEI
[AK4370]
■ Serial Data Interface
The AK4370 interfaces with external systems via the SDATA, BICK and LRCK pins. Five data formats are available,
selected by setting the DIF2, DIF1 and DIF0 bits (Table 6). Mode 0 is compatible with existing 16-bit DACs and digital
filters. Mode 1 is a 20-bit version of Mode 0. Mode 4 is a 24-bit version of Mode 0. Mode 2 is similar to AKM ADCs and
many DSP serial ports. Mode 3 is compatible with the I2S serial data protocol. In Modes 2 and 3 with BICK≥48fs, the
following formats are also valid: 16-bit data followed by eight zeros (17th to 24th bits) and 20-bit data followed by four
zeros (21st to 24th bits). In all modes, the serial data is MSB first and 2’s complement format.
When master mode and BICK=32fs(BF bit = “0”), the AK4370 cannot be set to Mode 1, Mode 2 and Mode4.
Mode
0
1
2
3
4
DIF2
0
0
0
0
1
DIF1
0
0
1
1
0
DIF0
0
1
0
1
0
Format
BICK
0: 16bit, LSB justified
32fs ≤ BICK ≤ 64fs
1: 20bit, LSB justified
40fs ≤ BICK ≤ 64fs
2: 24bit, MSB justified
48fs ≤ BICK ≤ 64fs
3: I2S Compatible
BICK=32fs or 48fs ≤ BICK ≤ 64fs
4: 24bit, LSB justified
48fs ≤ BICK ≤ 64fs
Table 6. Audio Data Format
Figure
Figure 13
Figure 14
Figure 15
Figure 16
Figure 14
Default
LRCK
BICK
(32fs)
SDATA
Mode 0
15
14
6
5
4
3
2
15
14
1
0
15
14
0
Don’t care
6
5
4
3
2
1
0
15
14
0
19
0
19
0
15
14
BICK
SDATA
Mode 0
Don’t care
15:MSB, 0:LSB
Lch Data
Rch Data
Figure 13. Mode 0 Timing (LRP = BCKP bits = “0”)
LRCK
BICK
SDATA
Mode 1
Don’t care
19
0
Don’t care
19
0
Don’t care
19:MSB, 0:LSB
SDATA
Mode 4
Don’t care
23
22
21
20
23
22
21
20
23:MSB, 0:LSB
Lch Data
Rch Data
Figure 14. Mode 1, 4 Timing (LRP = BCKP bits = “0”)
MS0595-E-00
2007/03
- 19 -
ASAHI KASEI
[AK4370]
Rch
Lch
LRCK
BICK
SDATA
15
14
0
19
18
4
1
0
23
22
8
3
4
Don’t
care
15
14
0
Don’t
care
19
18
4
1
0
Don’t
care
23
22
8
3
4
Don’t
care
15
14
Don’t
care
19
18
Don’t
care
23
22
16bit
SDATA
20bit
SDATA
1
0
1
0
24bit
Figure 15. Mode 2 Timing (LRP = BCKP bits = “0”)
Lch
LRCK
Rch
BICK
SDATA
16bit
SDATA
20bit
SDATA
24bit
15
14
0
19
18
4
1
0
23
22
8
3
4
1
0
15
14
6
5
4
3
2
Don’t
care
15
14
0
Don’t
care
19
18
4
1
0
Don’t
care
23
22
8
3
4
1
15
14
6
5
4
3
Don’t
care
15
Don’t
care
19
0
Don’t
care
23
2
1
BICK
(32fs)
SDATA
16bit
0
1
0
0
15
Figure 16. Mode 3 Timing (LRP = BCKP bits = “0”)
MS0595-E-00
2007/03
- 20 -
ASAHI KASEI
[AK4370]
■ Digital Attenuator
The AK4370 has a channel-independent digital attenuator (256 levels, 0.5dB step). This digital attenuator is placed before
the D/A converter. ATTL/R7-0 bits set the attenuation level (0dB to −127dB or MUTE) for each channel (Table 7). At
DATTC bit = “1”, ATTL7-0 bits control both channel’s attenuation levels. At DATTC bit = “0”, ATTL7-0 bits control
the left channel level and ATTR7-0 bits control the right channel level.
ATTL7-0
Attenuation
ATTR7-0
FFH
0dB
FEH
−0.5dB
FDH
−1.0dB
FCH
−1.5dB
:
:
:
:
02H
−126.5dB
01H
−127.0dB
00H
Default
MUTE (−∞)
Table 7. Digital Volume ATT values
The ATS bit sets the transition time between set values of ATT7-0 bits as either 1061/fs or 7424/fs (Table 8). When the
ATS bit = “0”, a soft transition between the set values occurs(1062 levels). It takes 1061/fs ([email protected]=44.1kHz) from
FFH(0dB) to 00H(MUTE). The ATTs are 00H when the PMDAC bit is “0”. When the PMDAC returns to “1”, the ATTs
fade to their current value. The digital attenuator is independent of the soft mute function.
ATT speed
0dB to MUTE
1 step
0
1061/fs
4/fs
Default
1
7424/fs
29/fs
Table 8. Transition time between set values of ATT7-0 bits
ATS
MS0595-E-00
2007/03
- 21 -
ASAHI KASEI
[AK4370]
■ Soft Mute
Soft mute operation is performed in the digital domain. When the SMUTE bit goes to “1”, the output signal is attenuated
by −∞ during the ATT_DATA×ATT transition time (Table 8) from the current ATT level. When the SMUTE bit is
returned 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 is returned to the ATT level by the same cycle. The soft mute is effective for changing the
signal source without stopping the signal transmission.
SMUTE bit
ATT Level
ATS bit
ATS bit
(1)
(1)
(3)
Attenuation
-∞
GD
(2)
GD
Analog Output
Figure 17. Soft Mute Function
Notes:
(1) ATT_DATA×ATT transition time (Table 8). For example, this time is 3712LRCK cycles (3712/fs) at ATS bit =
“1” and ATT_DATA = “128” (-63.5dB).
(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 operation, the attenuation is discontinued
and it is returned to the ATT level by the same cycle.
MS0595-E-00
2007/03
- 22 -
ASAHI KASEI
[AK4370]
■ De-emphasis Filter
The AK4370 includes a digital de-emphasis filter (tc = 50/15μs), using an IIR filter corresponding to three sampling
frequencies (32kHz, 44.1kHz and 48kHz). The de-emphasis filter is enabled by setting DEM1-0 bits (Table 9).
DEM1 bit
DEM0 bit
De-emphasis
0
0
44.1kHz
0
1
OFF
Default
1
0
48kHz
1
1
32kHz
Table 9. De-emphasis Filter Frequency Select
■ Bass Boost Function
By controlling the BST1-0 bits, a low frequency boost signal can be output from DAC. The setting value is common for
both channels (Table 10).
BST1 bit
BST0 bit
BOOST
0
0
OFF
0
1
MIN
1
0
MID
1
1
MAX
Table 10. Low Frequency Boost Select
Default
■ Digital Mixing Function
MONO1-0 bits select the digital data mixing for the DAC (Table 11).
MONO1 bit
0
0
1
1
MONO0 bit
Lch
0
L
1
L
0
R
1
(L+R)/2
Table 11. Mixer Setting
Rch
R
L
R
(L+R)/2
Default
■ System Reset
PDN pin should be held to “L” upon power-up. The 4370 should be reset by bringing PDN pin “L” for 150ns or more. All
of the internal register values are initialized by the system reset. After exiting reset, VCOM, DAC, HPL, HPR, LOUT and
ROUT switch to the power-down state. The contents of the control register are maintained until the reset is completed.
The DAC exits reset and power down states by MCKI after the PMDAC bit is changed to “1”. The DAC is in power-down
mode until MCKI is input.
MS0595-E-00
2007/03
- 23 -
ASAHI KASEI
[AK4370]
■ Headphone Output (HPL, HPR pins)
The power supply voltage for the headphone-amp is supplied from the HVDD pin and is centered on the MUTET voltage.
The headphone-amp output load resistance is 16Ω (min). When the MUTEN bit is “1” at PMHPL=PMHPR= “1”, the
common voltage rises to 0.475 x AVDD. When the MUTEN bit is “0”, the common voltage of the headphone-amp falls
and the outputs (HPL and HPR pins) go to VSS1.
70k x C (typ)
tr: Rise Time up to VCOM/2
tf: Fall Time down to VCOM/2
60k x C (typ)
Table 12. Headphone-Amp Rise/Fall Time
[Example] : Capacitor between the MUTET pin and ground = 1μF:
Rise time up to VCOM/2: tr = 70k x 1μ = 70ms (typ).
Fall time down to VCOM/2: tf = 60k x 1μ = 60ms (typ).
When the PMHPL and PMHPR bits are “0”, the headphone-amp is powered-down, and the outputs (HPL and HPR pins)
go to VSS1.
PMHPL/R bit
MUTEN bit
HPL/R pin
VCOM
VCOM/2
tf
tr
(1) (2)
(3)
(4)
Figure 18. Power-up/Power-down Timing for the Headphone-Amp
(1) Headphone-amp power-up (PMHPL and PMHPR bits = “1”). The outputs are still at VSS1.
(2) Headphone-amp common voltage rises up (MUTEN bit = “1”). Common voltage of the headphone-amp is rising. This
rise time depends on the capacitor value connected with the MUTET pin. The rise time up to VCOM/2 is tr = 70k x
C(typ) when the capacitor value on MUTET pin is “C”.
(3) Headphone-amp common voltage falls down (MUTEN bit = “0”). Common voltage of the headphone-amp is falling
to VSS1. This fall time depends on the capacitor value connected with the MUTET pin. The fall time down to
VCOM/2 is tf = 60k x C(typ) when the capacitor value on MUTET pin is “C”.
(4) Headphone-amp power-down (PMHPL, PMHPR bits = “0”). The outputs are at VSS1. If the power supply is switched
off or the headphone-amp is powered-down before the common voltage goes to VSS1, some pop noise may occur.
MS0595-E-00
2007/03
- 24 -
ASAHI KASEI
[AK4370]
< External Circuit of Headphone-Amp >
The cut-off frequency of the headphone-amp output depends on the external resistor and capacitor used. Table 13 shows
the cut off frequency and the output power for various resistor/capacitor combinations. The headphone impedance RL is
16Ω. Output powers are shown at AVDD = 2.4, 3.0 and 3.3V. The output voltage of the headphone-amp is 0.48 x AVDD
(Vpp) @−3dBFS.
HP-AMP
R
C
Headphone
16Ω
AK4370
Figure 19. External Circuit Example of Headphone
R [Ω]
C [μF]
0
6.8
16
220
100
100
47
100
47
fc [Hz]
BOOST=OFF
fc [Hz]
BOOST=MIN
Output Power [mW]
2.4V
3.0V
45
17
21
33
100
43
70
28
10
16
149
78
50
19
5
8
106
47
Table 13. Relationship of external circuit, output power and frequency response
3.3V
40
20
10
< Wired OR with External Headphone-Amp >
When PMVCM=PMHPL=PMHPR bits = “0” and HPZ bit = “1”, Headphone-amp is powered-down and HPL/R pins are
pulled-down to VSS1 by 200kΩ (typ). In this setting, it is available to connect headphone-amp of AK4370 and external
single supply headphone-amp by “wired OR”.
PMVCM
x
0
1
1
PMHPL/R
0
0
1
1
HPMTN
HPZ
Mode
x
0
Power-down & Mute
x
1
Power-down
0
x
Mute
1
x
Normal Operation
Table 14. HP-Amp Mode Setting (x: Don’t care)
HPL/R pins
VSS1
Pull-down by 200kΩ
VSS1
Normal Operation
Default
HPL pin
AK4370
Headphone
HPR pin
Another
HP-Amp
Figure 20. Wired OR with External HP-Amp
MS0595-E-00
2007/03
- 25 -
ASAHI KASEI
[AK4370]
< Analog Mixing Circuit for Headphone Output >
DALHL, LIN1HL, RIN1HL, LIN2HL and RIN2HL bits control each path switch of HPL output. DARHR, LIN1HR,
RIN1HR, LIN2HR and RIN2HR bits control each path switch of HPR output.
When L1HM=L2HM bits = “0”, HPG1-0 bits = “00” (R1H= R2H= RDH= 100k) and ATTH4-0 bits = “00H” (0dB), the
mixing gain is +0.95dB (typ). When HPG1-0 bit = “01” (RDH= 50k), the mixing gain of DAC path is +6.95dB (typ).
When HPG1-0 bit = “10” (RDH= 25k), the mixing gain of DAC path is +12.95dB (typ). When L1HM and L2HM bits are
“1”, LIN1/RIN1 and LIN2/RIN2 signals are output from HPL/R pins as (L+R)/2, respectively (R1H= R2H= 200k).
When LDIF=LDIFH=LIN1L=RIN1R bits = “1”, LIN1 and RIN1 pins becomes IN+ and IN− pins, respectively. IN+ and
IN− pins can be used as full-differential mono line input for analog mixing for headphone-amp. In this case, LIN1HL,
RIN1HL, LIN1HR and RIN1HR bits should be “0”.
If the path is OFF and the signal is input to the input pin, the input pin should be biased to a voltage equivalent to VCOM
voltage (= 0.475 x AVDD) externally. Figure 39 shows the external bias circuit example.
100k(typ)
Figure 23
LDIFH bit
R1H
LIN1 pin
LIN1HL bit
R1H
RIN1 pin
RIN1HL bit
R2H
LIN2 pin
LIN2HL bit
R2H
RIN2 pin
100k(typ)
1.11RH
RIN2HL bit
RDH
DAC Lch
DALHL bit
−
RH
+
−
HPL pin
+
HP-Amp
100k(typ)
Figure 23
LDIFH bit
R1H
LIN1 pin
LIN1HR bit
R1H
RIN1 pin
RIN1HR bit
R2H
LIN2 pin
LIN2HR bit
R2H
100k(typ)
RIN2 pin
1.11RH
RIN2HR bit
RDH
DAC Rch
DARHR bit
−
RH
+
−
+
HPR pin
HP-Amp
Figure 21. Summation circuit for HPL/R output
MS0595-E-00
2007/03
- 26 -
ASAHI KASEI
[AK4370]
■ Headphone Output Volume
HPL/HPR volume is controlled by ATTH4-0 bit when HMUTE bit = “0” (+12dB ∼ −51dB or +6dB ∼ −57dB or 0dB ∼
−63dB, 1.5dB or 3dB step, Table 15)
HMUTE
ATTH4-0
0
1
00H
01H
02H
03H
:
:
12H
13H
14H
15H
16H
:
:
1DH
1EH
1FH
x
HPG1-0 bits = “10”
HPG1-0 bits = “01”
HPG1-0 bits = “00”
(DAC Only)
(DAC Only)
+12dB
+6dB
0dB
+10.5dB
+4.5dB
−1.5dB
+9dB
+3dB
−3dB
+7.5dB
+1.5dB
−4.5dB
:
:
:
:
:
:
−15dB
−21dB
−27dB
−16.5dB
−22.5dB
−28.5dB
−18dB
−24dB
−30dB
−21dB
−27dB
−33dB
−24dB
−30dB
−36dB
:
:
:
:
:
:
−45dB
−51dB
−57dB
−48dB
−54dB
−60dB
−51dB
−57dB
−63dB
MUTE
MUTE
MUTE
Table 15. HPL/HPR Volume ATT values (x: Don’t care)
MS0595-E-00
STEP
Default
1.5dB
3dB
2007/03
- 27 -
ASAHI KASEI
[AK4370]
■ Stereo Line Output (LOUT, ROUT pins)
The common voltage is 0.475 x AVDD. The load resistance is 10kΩ(min). When the PMLO bit is “1”, the stereo line
output is powered-up. DALL, LIN1L, RIN1L, LIN2L and RIN2L bits control each path switch of LOUT. DARR, LIN1R,
RIN1R, LIN2R and RIN2R bits control each path switch of ROUT. When L1M = L2M bits = “0”, LOG bit = “0” (R1L =
R2L = RDL = 100k) and ATTS3-0 bits is “0FH”(0dB), the mixing gain is 0dB(typ) for all paths. When the LOG bit =
“1”(RDL= 50k), the DAC path gain is +6dB. When L1M = L2M bits = “1”, LIN1/RIN1 and LIN2/RIN2 signals are output
from LOUT/ROUT pins as (L+R)/2, respectively (R1L = R2L = 200k).
If the path is OFF and the signal is input to the input pin, the input pin should be biased to a voltage equivalent to VCOM
voltage (= 0.475 x AVDD) externally. Figure 39 shows the external bias circuit example.
R1L
LIN1 pin
LIN1L bit
R1L
RIN1 pin
RIN1L bit
R2L
LIN2 pin
LIN2L bit
R2L
100k(typ)
RIN2 pin
RL
RIN2L bit
RDL
DAC Lch
DALL bit
−
RL
+
−
LOUT pin
+
R1L
LIN1 pin
LIN1R bit
R1L
RIN1 pin
RIN1R bit
R2L
LIN2 pin
LIN2R bit
R2L
100k(typ)
RIN2 pin
RL
RIN2R bit
RDL
DAC Rch
DARR bit
−
RL
+
−
+
ROUT pin
Figure 22. Summation circuit for stereo line output
MS0595-E-00
2007/03
- 28 -
ASAHI KASEI
[AK4370]
< Analog Mixing Circuit of Full-differential Mono input >
When LDIF=LIN1L=RIN1R bits = “1”, LIN1 and RIN1 pins becomes IN+ and IN− pins, respectively. IN+ and IN− pins
can be used as full-differential mono line input for analog mixing of LOUT/ROUT pins. It is not available to mix with
other signal source for LOUT/ROUT outputs.
If the path is OFF and the signal is input to the input pin, the input pin should be biased to a voltage equivalent to VCOM
voltage (= 0.475 x AVDD) externally. Figure 39 shows the external bias circuit example.
Figure 21
R1L
IN− pin
100k(typ)
HPL/R pins
LDIFH bit
RL
LIN1L bit
100k(typ)
LDIF bit
−
RL
+
−
LOUT pin
+
RL
R1L
IN+ pin
100k(typ)
RL
RIN1R bit
−
−
+
ROUT pin
+
Figure 23. Summation circuit for stereo line output (Full-differential input, LOG bit = “0”)
■ Stereo Line Output (LOUT/ROUT pins) Volume
LOUT/ROUT volume is controlled by ATTS3-0 bits when LMUTE bit = “0” (+6dB ∼ −24dB or 0dB ∼ −30dB, 2dB step,
Table 16). Pop noise occurs when ATTS3-0 bits are changed.
LOG bit = “1”
LOG bit = “0”
(DAC Only)
FH
+6dB
0dB
EH
+4dB
−2dB
DH
+2dB
−4dB
CH
0dB
−6dB
:
:
:
:
:
:
1H
−22dB
−28dB
0H
−24dB
−30dB
x
MUTE
MUTE
Table 16. LOUT/ROUT Volume ATT values (x: Don’t care)
LMUTE
0
1
ATTS3-0
MS0595-E-00
Default
2007/03
- 29 -
ASAHI KASEI
[AK4370]
■ Power-Up/Down Sequence
1) DAC → HP-Amp
Power Supply
(10)
(1)
>150ns
PDN pin
Don’t care
(2) >0s
PMVCM bit
Don’t care
(3)
Don’t care
Don’t care
Clock Input
PMDAC bit
DAC Internal
State
PD
Normal Operation
PD
Normal Operation
PD
SDTI pin
DALHL,
DARHR bits
(4) >0s
PMHPL,
PMHPR bits
(4) >0s
(5) >2ms
(5) >2ms
MUTEN bit
ATTL7-0
ATTR7-0 bits
00H(MUTE)
FFH(0dB)
(8) GD (9) 1061/fs
(6)
FFH(0dB)
00H(MUTE)
(8)
(8) (9)
(7)
(6)
(9)
00H(MUTE)
(8) (9)
(7)
HPL/R pin
Figure 24. Power-up/down sequence of DAC and HP-amp (Don’t care: except Hi-Z)
(1) When AVDD and DVDD are supplied separately, AVDD should be powered-up after DVDD rises up to 1.6V or
more. When AVDD and HVDD are supplied separately, AVDD should be powered-up at the same time or earlier
than HVDD. PDN pin should be set to “H” at least 150ns after power is supplied.
(2) PMVCM and PMDAC bits should be changed to “1” after PDN pin goes “H”.
(3) External clocks (MCKI, BICK, LRCK) are needed to operate the DAC. When the PMDAC bit = “0”, these clocks
can be stopped. The headphone-amp can operate without these clocks.
(4) DALHL and DARHR bits should be changed to “1” after PMVCM and PMDAC bit is changed to “1”.
(5) PMHPL, PMHPR and MUTEN bits should be changed to “1” at least 2ms (in case external capacitance at VCOM pin
is 2.2μF) after the DALHL and DARHR bits are changed to “1”
(6) Rise time of the headphone-amp is determined by an external capacitor (C) of the MUTET pin. The rise time up to
VCOM/2 is tr = 70k x C(typ). When C=1μF, tr = 70ms(typ).
(7) Fall time of the headphone-amp is determined by an external capacitor (C) of the MUTET pin. The fall time down to
VCOM/2 is tf = 60k x C(typ). When C=1μF, tf = 60ms(typ).
PMHPL and PMHPR bits should be changed to “0” after HPL and HPR pins go to VSS1. After that, the DALHL and
DARHR bits should be changed to “0”.
(8) Analog output corresponding to the digital input has a group delay (GD) of 22/fs(=499µ[email protected]=44.1kHz).
(9) The ATS bit sets transition time of digital attenuator. Default value is 1061/fs([email protected]=44.1kHz).
(10) The power supply should be switched off after the headphone-amp is powered down (HPL/R pins become “L”).
When AVDD and DVDD are supplied separately, DVDD should be powered-down at the same time or later than
AVDD. When AVDD and HVDD are supplied separately, AVDD should be powered-down at the same time or later
than HVDD.
MS0595-E-00
2007/03
- 30 -
ASAHI KASEI
[AK4370]
2) DAC → Lineout
Power Supply
(1) >150ns
PDN pin
PMVCM bit
(2)
>0s
Don’t care
(5)
Clock Input
Don’t care
Don’t care
(4) >0s
PMDAC bit
DAC Internal
State
PD
Normal Operation
PD(Power-down)
Normal Operation
SDTI pin
DALL,
DARR bits
(3) >0s
PMLO bit
ATTL/R7-0 bits
LMUTE,
ATTS3-0 bits
FFH(0dB)
00H(MUTE)
FFH(0dB)
0FH(0dB)
10H(MUTE)
(7) GD
LOUT/ROUT pins
00H(MUTE)
(8) 1061/fs (7)
(6)
(8)
(7)
(Hi-Z)
(8)
(6)
(6)
(Hi-Z)
Figure 25. Power-up/down sequence of DAC and LOUT/ROUT (Don’t care: except Hi-Z)
(1) When AVDD and DVDD are supplied separately, AVDD should be powered-up after DVDD rises up to 1.6V or
more. When AVDD and HVDD are supplied separately, AVDD should be powered-up at the same time or earlier
than HVDD. PDN pin should be set to “H” at least 150ns after power is supplied.
(2) PMVCM bit should be changed to “1” after the PDN pin goes “H”.
(3) DALL and DARR bits should be changed to “1” after the PMVCM bit is changed to “1”.
(4) PMDAC and PMLO bits should be changed to “1” after DALL and DARR bits is changed to “1”.
(5) External clocks (MCKI, BICK, LRCK) are needed to operate the DAC. When the PMDAC bit = “0”, these clocks
can be stopped. The LOUT/ROUT buffer can operate without these clocks.
(6) When the PMLO bit is changed, pop noise is output from LOUT/ROUT pins.
(7) Analog output corresponding to the digital input has a group delay (GD) of 22fs([email protected]=44.1kHz).
(8) The ATS bit sets the transition time of the digital attenuator. Default value is 1061/fs([email protected]=44.1kHz).
MS0595-E-00
2007/03
- 31 -
ASAHI KASEI
[AK4370]
3) LIN1/RIN1/LIN2/RIN2 → HP-Amp
Power Supply
(1) >150ns
PDN pin
(2) >0s
PMVCM bit
Don’t care
LIN1HL, LIN2HL,
RIN1HR, RIN2HR bits
(3) >0s
PMHPL/R bits
(5) >2ms
(5) >2ms
MUTEN bit
(4)
LIN1/RIN1/
LIN2/RIN2 pins
(Hi-Z)
(Hi-Z)
(7)
(6)
(6)
HPL/R pins
Figure 26. Power-up/down sequence of LIN1/RIN1/LIN2/RIN2 and HP-Amp
(1) When AVDD and DVDD are supplied separately, AVDD should be powered-up after DVDD rises up to 1.6V or
more. When AVDD and HVDD are supplied separately, AVDD should be powered-up at the same time or earlier
than HVDD. PDN pin should be set to “H” at least 150ns after power is supplied. MCKI, BICK and LRCK can be
stopped when DAC is not used.
(2) PMVCM bit should be changed to “1” after PDN pin goes “H”.
(3) LIN1HL, LIN2HL, RIN1HR and RIN2HR bits should be changed to “1” after PMVCM bit is changed to “1”.
(4) When LIN1HL, LIN2HL, RIN1HR or RIN2HR bit is changed to “1”, LIN1, RIN1, LIN2 or RIN2 pin is biased to
0.475 x AVDD.
(5) PMHPL, PMHPR and MUTEN bits should be changed to “1” at least 2ms (in case external capacitance at VCOM pin
is 2.2μF) after LIN1HL, LIN2HL, RIN1HR and RIN2HR bits are changed to “1”.
(6) Rise time of the headphone-amp is determined by an external capacitor (C) of the MUTET pin. The rise time up to
VCOM/2 is tr = 70k x C(typ). When C=1μF, tr = 70ms(typ).
(7) Fall time of the headphone-amp is determined by an external capacitor (C) of the MUTET pin. The fall time down to
VCOM/2 is tf = 60k x C(typ). When C=1μF, tf = 60ms(typ).
PMHPL and PMHPR bits should be changed to “0” after HPL and HPR pins go to VSS1. After that, the LIN1HL,
LIN2HL, RIN1HR and RIN2HR bits should be changed to “0”.
MS0595-E-00
2007/03
- 32 -
ASAHI KASEI
[AK4370]
4) LIN1/RIN1/LIN2/RIN2 → Lineout
Power Supply
(1) >150ns
PDN pin
(2) >0s
PMVCM bit
Don’t care
(3) >0s
LIN1L, RIN1R,
LIN2L, RIN2R bits
PMLO bit
(5) >2ms
(5) >2ms
(Hi-Z)
(4)
LIN1/RIN1/
LIN2/RIN2 pins
(Hi-Z)
LMUTE,
ATTS3-0 bits
0FH(0dB)
10H(MUTE)
LOUT/ROUT pins
(6)
(6)
(Hi-Z)
(6)
(Hi-Z)
Figure 27. Power-up/down sequence of LIN1/RIN1/LIN2/RIN2 and Lineout
(1) When AVDD and DVDD are supplied separately, AVDD should be powered-up after DVDD rises up to 1.6V or
more. When AVDD and HVDD are supplied separately, AVDD should be powered-up at the same time or earlier
than HVDD. PDN pin should be set to “H” at least 150ns after power is supplied. MCKI, BICK and LRCK can be
stopped when DAC is not used.
(2) PMVCM bit should be changed to “1” after PDN pin goes “H”.
(3) LIN1L, LIN2L, RIN1R and RIN2R bits should be changed to “1” after PMVCM bit is changed to “1”.
(4) When LIN1L, LIN2L, RIN1R or RIN2R bit is changed to “1”, LIN1, RIN1, LIN2 or RIN2 pin is biased to 0.475 x
AVDD.
(5) PMLO bit should be changed to “1” at least 2ms (in case external capacitance at VCOM pin is 2.2μF) after LIN1L,
LIN2L, RIN1R and RIN2R bits are changed to “1”.
(6) When the PMLO bit is changed, pop noise is output from LOUT/ROUT pins.
MS0595-E-00
2007/03
- 33 -
ASAHI KASEI
[AK4370]
■ Serial Control Interface
(1) 3-wire Serial Control Mode (I2C pin = “L”)
Internal registers may be written to via the 3-wire μP interface pins (CSN, CCLK and CDTI). The data on this interface
consists of the Chip address (2-bits, Fixed to “01”), Read/Write (1-bit, Fixed to “1”, Write only), Register address (MSB
first, 5-bits) and Control data (MSB first, 8-bits). Address and data are clocked in on the rising edge of CCLK. For write
operations, the data is latched after a low-to-high transition of the 16th CCLK. CSN should be set to “H” once after 16
CCLKs for each address. The clock speed of CCLK is 5MHz(max). The value of the internal registers is initialized at
PDN pin = “L”.
CSN
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
CCLK
CDTI
C1 C0 R/W A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
C1-C0:
R/W:
A4-A0:
D7-D0:
Chip Address (Fixed to “01”)
READ/WRITE (Fixed to “1”, Write only)
Register Address
Control Data
Figure 28. 3-wire Serial Control I/F Timing
MS0595-E-00
2007/03
- 34 -
ASAHI KASEI
[AK4370]
(2) I2C-bus Control Mode (I2C pin = “H”)
The AK4370 supports fast-mode I2C-bus (max: 400kHz, Version 1.0).
(2)-1. WRITE Operations
Figure 29 shows the data transfer sequence for the I2C-bus mode. All commands are preceded by a START condition. A
HIGH to LOW transition on the SDA line while SCL is HIGH indicates a START condition (Figure 35). After the
START condition, a slave address is sent. This address is 7 bits long followed by the eighth bit that is a data direction bit
(R/W). The most significant six bits of the slave address are fixed as “001000”. The next bit is CAD0 (device address bit).
This bit identifies the specific device on the bus. The hard-wired input pin (CAD0 pin) sets this device address bit (Figure
30). If the slave address matches that of the AK4370, the AK4370 generates an acknowledgement and the operation is
executed. The master must generate the acknowledge-related clock pulse and release the SDA line (HIGH) during the
acknowledge clock pulse (Figure 36). A R/W bit value of “1” indicates that the read operation is to be executed. A “0”
indicates that the write operation is to be executed.
The second byte consists of the control register address of the AK4370. The format is MSB first, and those most
significant 3-bits are fixed to zeros (Figure 31). The data after the second byte contains control data. The format is MSB
first, 8bits (Figure 32). The AK4370 generates an acknowledgement after each byte has been received. A data transfer is
always terminated by a STOP condition generated by the master. A LOW to HIGH transition on the SDA line while SCL
is HIGH defines a STOP condition (Figure 35).
The AK4370 can perform more than one byte write operation per sequence. After receiving the third byte the AK4370
generates an acknowledgement and awaits the next data. The master can transmit more than one byte instead of
terminating the write cycle after the first data byte is transferred. After receiving each data packet the internal 5-bit
address counter is incremented by one, and the next data is automatically taken into the next address. If the address
exceeds 13H prior to generating the stop condition, the address counter will “roll over” to 00H and the previous data will
be overwritten.
The data on the SDA line must remain stable during the HIGH period of the clock. The HIGH or LOW state of the data
line can only change when the clock signal on the SCL line is LOW(Figure 37) except for the START and STOP
conditions.
S
T
A
R
T
SDA
S
T
O
P
R/W="0"
Slave
S Address
Sub
Address(n)
Data(n)
A
C
K
A
C
K
Data(n+1)
A
C
K
Data(n+x)
A
C
K
A
C
K
P
A
C
K
Figure 29. Data Transfer Sequence at the I2C-Bus Mode
0
0
1
0
0
0
CAD0
R/W
A2
A1
A0
D2
D1
D0
(Those CAD0 should match with CAD0 pin)
Figure 30. The First Byte
0
0
0
A4
A3
Figure 31. The Second Byte
D7
D6
D5
D4
D3
Figure 32. Byte Structure after the second byte
MS0595-E-00
2007/03
- 35 -
ASAHI KASEI
[AK4370]
(2)-2. READ Operations
Set the R/W bit = “1” for the READ operation of the AK4370. After a transmission of data, the master can read the next
address’s data by generating an acknowledge instead of terminating the writing cycle after receiving the first data word.
After receiving each data packet the internal 5-bit address counter is incremented by one, and the next data is
automatically taken into the next address. If the address exceeds 13H prior to generating a stop condition, the address
counter will “roll over” to 00H and the previous data will be overwritten.
The AK4370 supports two basic read operations: CURRENT ADDRESS READ and RANDOM ADDRESS READ.
(2)-2-1. CURRENT ADDRESS READ
The AK4370 contains an internal address counter that maintains the address of the last word accessed, incremented by
one. Therefore, if the last access (either a read or write) were to address n, the next CURRENT READ operation would
access data from the address n+1. After receiving the slave address with R/W bit set to “1”, the AK4370 generates an
acknowledge, transmits 1-byte of data to the address set by the internal address counter and increments the internal
address counter by 1. If the master does not generate an acknowledgement to the data but instead generates a stop
condition, the AK4370 ceases transmission.
S
T
A
R
T
SDA
S
T
O
P
R/W="1"
Slave
S Address
Data(n)
A
C
K
Data(n+1)
A
C
K
Data(n+2)
A
C
K
Data(n+x)
A
C
K
A
C
K
P
A
C
K
Figure 33. CURRENT ADDRESS READ
(2)-2-2. RANDOM ADDRESS READ
The random read operation allows the master to access any memory location at random. Prior to issuing the slave address
with the R/W bit set to “1”, the master must first perform a “dummy” write operation. The master issues a start request, a
slave address (R/W bit = “0”) and then the register address to read. After the register address is acknowledged, the master
immediately reissues the start request and the slave address with the R/W bit set to “1”. The AK4370 then generates an
acknowledgement, 1 byte of data and increments the internal address counter by 1. If the master does not generate an
acknowledgement to the data but instead generates a stop condition, the AK4370 ceases transmission.
S
T
A
R
T
SDA
S
T
A
R
T
R/W="0"
Slave
S Address
Slave
S Address
Sub
Address(n)
A
C
K
A
C
K
S
T
O
P
R/W="1"
Data(n)
A
C
K
Data(n+1)
A
C
K
Data(n+x)
A
C
K
A
C
K
P
A
C
K
Figure 34. RANDOM ADDRESS READ
MS0595-E-00
2007/03
- 36 -
ASAHI KASEI
[AK4370]
SDA
SCL
S
P
start condition
stop condition
Figure 35. START and STOP Conditions
DATA
OUTPUT BY
TRANSMITTER
not acknowledge
DATA
OUTPUT BY
RECEIVER
acknowledge
SCL FROM
MASTER
2
1
8
9
S
clock pulse for
acknowledgement
START
CONDITION
Figure 36. Acknowledge on the I2C-Bus
SDA
SCL
data line
stable;
data valid
change
of data
allowed
Figure 37. Bit Transfer on the I2C-Bus
MS0595-E-00
2007/03
- 37 -
ASAHI KASEI
[AK4370]
■ Register Map
Addr
00H
01H
02H
03H
04H
05H
06H
07H
08H
09H
0AH
0BH
0CH
0DH
0EH
0FH
10H
11H
12H
13H
Register Name
Power Management
Clock Control 0
Clock Control 1
Mode Control 0
Mode Control 1
DAC Lch ATT
DAC Rch ATT
Headphone Out Select 0
Lineout Select 0
Lineout ATT
Reserved
Reserved
Reserved
Headphone Out Select 1
Headphone ATT
Lineout Select 1
Mono Mixing
Differential Select
Reserved
Reserved
D7
D6
D5
D4
D3
D2
D1
D0
0
FS3
0
0
ATS
ATTL7
ATTR7
HPG1
0
0
0
0
0
0
0
0
0
0
0
0
0
FS2
0
MONO1
DATTC
ATTL6
ATTR6
HPG0
LOG
0
0
0
0
0
HPZ
0
0
0
0
0
PMLO
FS1
M/S
MONO0
LMUTE
ATTL5
ATTR5
LIN2HR
LIN2R
0
0
0
0
0
HMUTE
0
0
0
0
0
MUTEN
FS0
MCKAC
BCKP
SMUTE
ATTL4
ATTR4
LIN2HL
LIN2L
0
0
0
0
0
ATTH4
0
0
0
0
1
PMHPR
0
BF
LRP
BST1
ATTL3
ATTR3
RIN1HR
RIN1R
ATTS3
0
0
0
RIN2HR
ATTH3
RIN2R
L2M
0
0
0
PMHPL
0
0
DIF2
BST0
ATTL2
ATTR2
LIN1HL
LIN1L
ATTS2
0
0
0
RIN2HL
ATTH2
RIN2L
L2HM
0
0
0
PMDAC
0
0
DIF1
DEM1
ATTL1
ATTR1
DARHR
DARR
ATTS1
0
0
0
LIN1HR
ATTH1
LIN1R
L1M
LDIFH
0
0
PMVCM
0
0
DIF0
DEM0
ATTL0
ATTR0
DALHL
DALL
ATTS0
0
0
0
RIN1HL
ATTH0
RIN1L
L1HM
LDIF
0
0
All registers inhibit writing at PDN pin = “L”.
PDN pin = “L” resets the registers to their default values.
For addresses from 14H to 1FH, data must not be written.
Unused bits must contain a “0” value.
Unused bits must contain a “1” value
MS0595-E-00
2007/03
- 38 -
ASAHI KASEI
[AK4370]
■ Register Definitions
Addr
00H
Register Name
Power Management 0
R/W
Default
D7
0
RD
0
D6
0
RD
0
D5
PMLO
R/W
0
D4
MUTEN
R/W
0
D3
PMHPR
R/W
0
D2
PMHPL
R/W
0
D1
PMDAC
R/W
0
D0
PMVCM
R/W
0
PMVCM: Power Management for VCOM Block
0: Power OFF (Default)
1: Power ON
PMDAC: Power Management for DAC Blocks
0: Power OFF (Default)
1: Power ON
When the PMDAC bit is changed from “0” to “1”, the DAC is powered-up to the current register values
(ATT value, sampling rate, etc).
PMHPL: Power Management for the left channel of the headphone-amp
0: Power OFF (Default). HPL pin goes to VSS1(0V).
1: Power ON
PMHPR: Power Management for the right channel of the headphone-amp
0: Power OFF (Default). HPR pin goes to VSS1(0V).
1: Power ON
MUTEN: Headphone Amp Mute Control
0: Mute (Default). HPL and HPR pins go to VSS1(0V).
1: Normal operation. HPL and HPR pins go to 0.475 x AVDD.
PMLO: Power Management for Stereo Output
0: Power OFF (Default) LOUT/ROUT pins go to Hi-Z.
1: Power ON
Each block can be powered-down respectively by writing “0” in each bit of this address. When the PDN pin is “L”,
all blocks are powered-down regardless as setting of this address. In this case, register is initialized to the default
value.
When PMVCM, PMDAC, PMHPL, PMHPR and PMLO bits are “0”, all blocks are powered-down. The register
values remain unchanged. Power supply current is 20μA(typ) in this case. For fully shut down (typ. 1μA), PDN pin
should be “L”.
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ASAHI KASEI
Addr
01H
[AK4370]
Register Name
Clock Control 0
R/W
Default
D7
FS3
R/W
1
D6
FS2
R/W
0
D5
FS1
R/W
0
D4
FS0
R/W
0
D6
0
RD
0
D5
M/S
R/W
0
D4
MCKAC
R/W
0
D3
0
RD
0
D2
0
RD
0
D1
0
RD
0
D0
0
RD
0
D3
BF
R/W
0
D2
0
RD
0
D1
0
RD
0
D0
0
RD
0
D2
DIF2
R/W
0
D1
DIF1
R/W
1
D0
DIF0
R/W
0
FS3-0: Sampling Frequency select
See Table 2.
Addr
02H
Register Name
Clock Control 1
R/W
Default
D7
0
RD
0
BF: BICK Period setting in Master Mode. In slave mode, this bit is ignored.
0: 32fs (Default)
1: 64fs
MCKAC: MCKI Input Mode Select
0: CMOS input (Default)
1: AC coupling input
M/S: Master/Slave Mode Select
0: Slave mode (Default)
1: Master mode
Addr
03H
Register Name
Mode Control 0
R/W
Default
D7
0
RD
0
D6
MONO1
R/W
0
D5
MONO0
R/W
0
D4
BCKP
R/W
0
D3
LRP
R/W
0
DIF2-0: Audio Data Interface Format Select (Table 6)
Default: “010” (Mode 2)
LRP: LRCK Polarity Select in Slave Mode
0: Normal (Default)
1: Invert
BCKP: BICK Polarity Select in Slave Mode
0: Normal (Default)
1: Invert
MONO1-0: Mixing Select (Table 11)
Default: “00” (LR)
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ASAHI KASEI
Addr
04H
Register Name
Mode Control 1
R/W
Default
[AK4370]
D7
ATS
R/W
0
D6
DATTC
R/W
0
D5
LMUTE
R/W
1
D4
SMUTE
R/W
0
D3
BST1
R/W
0
D2
BST0
R/W
0
D1
DEM1
R/W
0
D0
DEM0
R/W
1
DEM1-0: De-emphasis Filter Frequency Select (Table 9)
Default: “01” (OFF)
BST1-0: Low Frequency Boost Function Select (Table 10)
Default: “00” (OFF)
SMUTE: Soft Mute Control
0: Normal operation (Default)
1: DAC outputs soft-muted
LMUTE: Mute control for LOUT/ROUT (Note 19)
0: Normal operation. ATTS3-0 bits control attenuation value.
1: Mute. ATTS3-0 bits are ignored. (Default)
DATTC: DAC Digital Attenuator Control Mode Select
0: Independent (Default)
1: Dependent
At DATTC bit = “1”, ATTL7-0 bits control both channel attenuation levels, while register values of
ATTL7-0 bits are not written to the ATTR7-0 bits. At DATTC bit = “0”, the ATTL7-0 bits control the left
channel level and the ATTR7-0 bits control the right channel level.
ATS: Digital attenuator transition time setting (Table 8)
0: 1061/fs (Default)
1: 7424/fs
Addr
05H
06H
Register Name
DAC Lch ATT
DAC Rch ATT
R/W
Default
D7
ATTL7
ATTR7
R/W
0
D6
ATTL6
ATTR6
R/W
0
D5
ATTL5
ATTR5
R/W
0
D4
ATTL4
ATTR4
R/W
0
D3
ATTL3
ATTR3
R/W
0
D2
ATTL2
ATTR2
R/W
0
D1
ATTL1
ATTR1
R/W
0
D0
ATTL0
ATTR0
R/W
0
ATTL7-0: Setting of the attenuation value of output signal from DACL (Table 7)
ATTR7-0: Setting of the attenuation value of output signal from DACR (Table 7)
Default: “00H” (MUTE)
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ASAHI KASEI
Addr
07H
Register Name
Headphone Out Select 0
R/W
Default
[AK4370]
D7
HPG1
R/W
0
D6
HPG0
R/W
0
D5
LIN2HR
R/W
0
D4
LIN2HL
R/W
0
D3
RIN1HR
R/W
0
D2
LIN1HL
R/W
0
D1
DARHR
R/W
0
D0
DALHL
R/W
0
DALHL: DAC left channel output signal is added to the left channel of the headphone-amp.
0: OFF (Default)
1: ON
DARHR: DAC right channel output signal is added to the right channel of the headphone-amp.
0: OFF (Default)
1: ON
LIN1HL: Input signal to LIN1 pin is added to the left channel of the headphone-amp.
0: OFF (Default)
1: ON
RIN1HR: Input signal to RIN1 pin is added to the right channel of the headphone-amp.
0: OFF (Default)
1: ON
LIN2HL: Input signal to LIN2 pin is added to the left channel of the headphone-amp.
0: OFF (Default)
1: ON
LIN2HR: Input signal to LIN2 pin is added to the right channel of the headphone-amp.
0: OFF (Default)
1: ON
HPG1-0: DAC Æ HPL/R Gain (Note 18)
Default: “00”: +0.95dB
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ASAHI KASEI
Addr
08H
[AK4370]
Register Name
Lineout Select 0
R/W
Default
D7
0
RD
0
D6
LOG
R/W
0
D5
LIN2R
R/W
0
D4
LIN2L
R/W
0
D3
RIN1R
R/W
0
D2
LIN1L
R/W
0
D1
DARR
R/W
0
D0
DALL
R/W
0
D3
ATTS3
R/W
0
D2
ATTS2
R/W
0
D1
ATTS1
R/W
0
D0
ATTS0
R/W
0
DALL: DAC left channel output is added to the LOUT buffer amp.
0: OFF (Default)
1: ON
DARR: DAC right channel output is added to the ROUT buffer amp.
0: OFF (Default)
1: ON
LIN1L: Input signal to the LIN1 pin is added to the LOUT buffer amp.
0: OFF (Default)
1: ON
RIN1R: Input signal to the RIN1 pin is added to the ROUT buffer amp.
0: OFF (Default)
1: ON
LIN2L: Input signal to the LIN2 pin is added to the LOUT buffer amp.
0: OFF (Default)
1: ON
LIN2R: Input signal to the LIN2 pin is added to the ROUT buffer amp.
0: OFF (Default)
1: ON
LOG: DAC Æ LOUT/ROUT Gain
0: 0dB (Default)
1: +6dB
Addr
09H
Register Name
Lineout ATT
R/W
Default
D7
0
RD
0
D6
0
RD
0
D5
0
RD
0
D4
0
RD
0
ATTS3-0: Analog volume control for LOUT/ROUT (Table 16)
Default: LMUTE bit = “1”, ATTS3-0 bits = “0000” (MUTE)
Setting of ATTS3-0 bits is enabled at LMUTE bit is “0”.
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ASAHI KASEI
Addr
0DH
[AK4370]
Register Name
Headphone Out Select 1
R/W
Default
D7
0
RD
0
D6
0
RD
0
D5
0
RD
0
D4
0
RD
0
D3
RIN2HR
R/W
0
D2
RIN2HL
R/W
0
D1
LIN1HR
R/W
0
D0
RIN1HL
R/W
0
D2
ATTH2
R/W
0
D1
ATTH1
R/W
0
D0
ATTH0
R/W
0
RIN1HL: RIN1 signal is added to the left channel of the Headphone-Amp
0: OFF (Default)
1: ON
LIN1HR: LIN1 signal is added to the right channel of the Headphone-Amp
0: OFF (Default)
1: ON
RIN2HL: RIN2 signal is added to the left channel of the Headphone-Amp
0: OFF (Default)
1: ON
RIN2HR: RIN2 signal is added to the right channel of the Headphone-Amp
0: OFF (Default)
1: ON
Addr
0EH
Register Name
Headphone ATT
R/W
Default
D7
0
RD
0
D6
HPZ
R/W
0
D5
HMUTE
R/W
0
D4
ATTH4
R/W
0
D3
ATTH3
R/W
0
ATTH4-0: Setting of the attenuation value of output signal from Headphone (Table 15)
Default: HMUTE bit = “0”, ATTH4-0 bits = “00” (0dB)
Setting of ATTH4-0 bits is enabled at HMUTE bit is “0”.
HMUTE: Mute control for Headphone-Amp
0: Normal operation. ATTH4-0 bits control attenuation value. (Default)
1: Mute. ATTH4-0 bits are ignored.
HPZ: Headphone-Amp Pull-down Control
0: Shorted to GND (Default)
1: Pulled-down by 200kΩ (typ)
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ASAHI KASEI
Addr
0FH
Register Name
Lineout Select
R/W
Default
[AK4370]
D7
0
RD
0
D6
0
RD
0
D5
0
RD
0
D4
0
RD
0
D3
RIN2R
R/W
0
D2
RIN2L
R/W
0
D1
LIN1R
R/W
0
D0
RIN1L
R/W
0
D4
0
RD
0
D3
L2M
R/W
0
D2
L2HM
R/W
0
D1
L1M
R/W
0
D0
L1HM
R/W
0
D3
0
RD
0
D2
0
RD
0
D1
LDIFH
R/W
0
D0
LDIF
R/W
0
RIN1L: RIN1 signal is added to the left channel of the Lineout
0: OFF (Default)
1: ON
LIN1R: LIN1 signal is added to the right channel of the Lineout
0: OFF (Default)
1: ON
RIN2L: RIN2 signal is added to the left channel of the Lineout
0: OFF (Default)
1: ON
RIN2R: RIN2 signal is added to the right channel of the Lineout
0: OFF (Default)
1: ON
Addr
10H
Register Name
Mono Mixing
R/W
Default
D7
0
RD
0
D6
0
RD
0
D5
0
RD
0
L1HM: LIN1/RIN1 signal is added to Headphone-Amp as (L+R)/2.
0: OFF (Default)
1: ON
L1M: LIN1/RIN1 signal is added to LOUT/ROUT as (L+R)/2.
0: OFF (Default)
1: ON
L2HM: LIN2/RIN2 signal is added to Headphone-Amp as (L+R)/2.
0: OFF (Default)
1: ON
L2M: LIN2/RIN2 signal is added to LOUT/ROUT as (L+R)/2.
0: OFF (Default)
1: ON
Addr
11H
Register Name
Differential Select
R/W
Default
D7
0
RD
0
D6
0
RD
0
D5
0
RD
0
D4
0
RD
0
LDIF: Switch control from IN+/IN− pin to LOUT/ROUT.
0: OFF (Default)
1: ON
When LDIF bit = “1”, LIN1 and RIN1 pins become IN+ and IN− pins respectively
LDIFH: Switch control from IN+/IN− pin to Headphone-Amp. (Setting of LIDFH bit is enable at LDIF bit = “1”)
0: OFF (Default)
1: ON
MS0595-E-00
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ASAHI KASEI
[AK4370]
SYSTEM DESIGN
Figure 38 shows the system connection diagram. An evaluation board [AKD4370] is available which demonstrates the
optimum layout, power supply arrangements and measurement results.
Analog Supply
+
1.6∼3.6V
10µ
0.1µ
Speaker
2.2µ
+
16
15
14
13
AVDD
VCOM
ROUT
LOUT
SPK-Amp
19 HPR
MUTET
12
20 HPL
I2C
11
21 RIN2
AK4370VN
PDN
10
22 LIN2
Top View
MCKI
DVDD
VSS2
5
6
7
LRCK
CDTI
4
24 LIN1
3
8
BICK
9
CCLK
SDATA
CSN
23 RIN1
2
Headphone
17
16Ω
1
16Ω
18
+
220µ
HVDD
220µ
+
VSS1
0.1µ
1µ
10
1000p
0.1µ
Analog Ground
Digital Ground
Audio Controller
µP
Notes:
- VSS1 and VSS2 of the AK4370 should be distributed separately from the ground of external controllers.
- All digital input pins (I2C, SDA/CDTI, SCL/CCLK, CAD0/CSN, SDATA, LRCK, BICK, MCKI, PDN) must
not be left floating.
- When the AK4370 is used in master mode, LRCK and BICK pins are floating before the M/S bit is changed to
“1”. Therefore, a 100kΩ pull-up resistor should be connected to the LRCK and BICK pins of the AK4370.
- When DVDD is supplied from AVDD via 10Ω series resistor, the capacitor larger than 0.1μF should not be
connected between DVDD and the ground.
Figure 38. Typical Connection Diagram (In case of AC coupling to MCKI)
MS0595-E-00
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ASAHI KASEI
[AK4370]
AVDD
AK4370
110k
LIN1 pin
HP-Amp
LIN1HL bit
100k
Note: If the path is OFF and the signal is input to the input pin, the input pin should be biased to a voltage equivalent to
VCOM voltage (= 0.475 x AVDD) externally.
Figure 39. External Bias Circuit Example for Line Input Pin
1. Grounding and Power Supply Decoupling
The AK4370 requires careful attention to power supply and grounding arrangements. AVDD and HVDD are usually
supplied from the analog power supply in the system and DVDD is supplied from AVDD via a 10Ω resistor. Alternatively
if AVDD and DVDD are supplied separately, AVDD should be powered-up after DVDD rises up to 1.6V or more. When
the AK4370 is powered-down, DVDD should be powered-down at the same time or later than AVDD. When AVDD and
HVDD are supplied separately, AVDD should be powered-up at the same time or earlier than HVDD. When the AK4370
is powered-down, AVDD should be powered-down at the same time or later than HVDD. VSS1 and VSS2 must be
connected to the analog ground plane. System analog ground and digital ground should be connected together near to
where the supplies are brought onto the printed circuit board. Decoupling capacitors should be as close to the AK4370 as
possible, with the small value ceramic capacitors being the nearest.
2. Voltage Reference
The input voltage to AVDD sets the analog output range. Usually a 0.1μF ceramic capacitor is connected between AVDD
and VSS1. VCOM is a signal ground of this chip (0.475 x AVDD). The electrolytic capacitor around 2.2μF attached
between VCOM anVSS1 eliminates the effects of high frequency noise, too. No load current may be drawn from VCOM
pin. All signals, especially clock, should be kept away from AVDD and VCOM in order to avoid unwanted coupling into
the AK4370.
3. Analog Outputs
The analog outputs are single-ended outputs, and 0.48 x AVDD Vpp(typ)@−3dBFS for headphone-amp and
0.61xAVDD Vpp(typ) @0dBFS for LOUT/ROUT centered on the VCOM voltage. The input data format is 2’s
compliment. The output voltage is a positive full scale for 7FFFFFH(@24bit) and negative full scale for
800000H(@24bit). The ideal output is VCOM voltage for 000000H(@24bit).
DC offsets on the analog outputs is eliminated by AC coupling since the analog outputs have a DC offset equal to VCOM
plus a few mV.
MS0595-E-00
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ASAHI KASEI
[AK4370]
PACKAGE
24pin QFN (Unit: mm)
4.0 ± 0.1
2.4 ± 0.15
13
18
19
2.4± 0.15
4.0 ± 0.1
12
A
Exposed
Pad
24
7
0.40 ± 0.1
6
1
B
0.5
0.2
0.08
0.10 M
PIN #1 ID
(0.35 x 45 )
0.75± 0.05
0.23 ± 0.05
Note) The exposed pad on the bottom surface of the package must be open or connected to the ground.
■ Package & Lead frame material
Package molding compound: Epoxy
Lead frame material:
Cu
Lead frame surface treatment: Solder (Pb free) plate
MS0595-E-00
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ASAHI KASEI
[AK4370]
MARKING
4370
XXXX
1
XXXX: Date code (4 digit)
Revision History
Date (YY/MM/DD)
07/03/23
Revision
00
Reason
First Edition
Page
Contents
IMPORTANT NOTICE
• These products and their specifications are subject to change without notice. Before considering any use or
application, consult the Asahi Kasei Microsystems Co., Ltd. (AKM) sales office or authorized distributor
concerning their current status.
• AKM assumes no liability for infringement of any patent, intellectual property, or other right in the
application or use of any information contained herein.
• 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 materials.
• 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 written 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 standards of performance and reliability.
• It is the responsibility of the buyer or distributor of an AKM product who distributes, disposes of, or
otherwise places the product with a third party to notify that party in advance of the above content and
conditions, and the buyer or distributor 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.
MS0595-E-00
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