
ASAHI KASEI 
[AK4343] 
MS0478-E-01 
2006/10 
- 91 - 
Headphone-amp Output
FS3-0 bits
(Addr:05H, D5&D2-0)
DVL/R7-0 bits
(Addr:0AH&0DH, D7-0)
PMHPL/R bits
(Addr:01H, D5-4)
HPMTN bit
(Addr:01H, D6)
HPL/R pins
1,111
0,000
18H
28H
Normal Output
(1)
BST1-0 bits
(Addr:0EH, D3-2)
00
10
00
(3)
(5)
(12)
PMDAC bit
(Addr:00H, D2)
(6)
(11)
(7)
(9)
(8)
(10)
IVL/R7-0 bits
(Addr:09H&0CH, D7-0)
E1H
91H
(4)
PMMIN bit
(Addr:00H, D5)
DACH bit
(Addr:0FH, D0)
(2)
(13)
Example:
PLL, Master Mode 
Audio I/F Format :MSB justified (ADC & DAC)  
Sampling Frequency: 44.1kHz 
Bass Boost Level : Middle  
8dB 
(1) Addr:05H, Data:27H 
(2) Addr:0FH, Data:09H 
(4) Addr:09H&0CH, Data:91H  
(5) Addr:0AH&0DH, Data:28H 
(6) Addr:00H, Data:64H 
(7) Addr:01H, Data:39H 
(8) Addr:01H, Data:79H
Playback 
(9) Addr:01H, Data:39H 
(10) Addr:01H, Data:09H  
(11) Addr:00H, Data:40H  
(3) Addr:0EH, Data:19H  
(12) Addr:0EH, Data:11H  
(13) Addr:0FH, Data:08H  
Figure 81. Headphone-Amp Output Sequence 
 <Example> 
At first, clocks should be supplied according to “Clock Set Up” sequence. 
(1) Set up a sampling frequency (FS3-0 bits). When the AK4343 is PLL mode, DAC and Speaker-Amp should be 
powered-up in consideration of PLL lock time after a sampling frequency is changed. 
(2) Set up the path of “DAC 
→
 HP-Amp”: DACH bit = “0” 
→
 “1” 
(3) Set up the low frequency boost level (BST1-0 bits) 
(4) Set up the ALC Block Digital Volume (Addr: 09H and 0CH) 
AVL7-0 and AVR7-0 bits should be set to “91H”(0dB). 
(5) Set up the output digital volume (Addr: 0AH and 0DH) 
When DVOLC bit is “1” (default), DVL7-0 bits set the volume of both channels. After DAC is powered-up, 
the digital volume changes from default value (0dB) to the register setting value by the soft transition. 
(6) Power up DAC and MIN-Amp: PMDAC = PMMIN bits = “0” 
→
 “1” 
The DAC enters an initialization cycle that starts when the PMDAC bit is changed from “0” to “1”. The 
initialization cycle time is 1059/fs=24ms@fs=44.1kHz. During the initialization cycle, the DAC input digital 
data of both channels are internally forced to a 2's compliment, “0”. The DAC output reflects the digital input 
data after the initialization cycle is complete. When ALC bit is “1”, ALC is disable (ALC gain is set by 
AVL/R7-0 bits) during an intialization cycle (1059/fs=24ms@fs=44.1kHz). After the initialization cycle, 
ALC operation starts from the gain set by AVL/R7-0 bits. 
(7) Power up headphone-amp: PMHPL = PMHPR bits = “0” 
→
 “1” 
Output voltage of headphone-amp is still HVSS. 
(8) Rise up the common voltage of headphone-amp: HPMTN bit = “0” 
→
 “1” 
The rise time depends on HVDD and the capacitor value connected with the MUTET pin. When HVDD=3.3V 
and the capacitor value is 1.0
μ
F, the time constant is 
τ
r
 = 100ms(typ), 250ms(max). 
(9) Fall down the common voltage of headphone-amp: HPMTN bit = “1” 
→
 “0” 
The fall time depends on HVDD and the capacitor value connected with the MUTET pin. When HVDD=3.3V 
and the capacitor value is 1.0
μ
F, the time constant is 
τ
 f
 = 100ms(typ), 250ms(max). 
If the power supply is powered-off or headphone-Amp is powered-down before the common voltage goes to 
GND, the pop noise occurs. It takes twice of 
τ
f 
that the common voltage goes to GND. 
(10) Power down headphone-amp: PMHPL = PMHPR bits = “1” 
→
 “0” 
(11) Power down DAC and MIN-Amp: PMDAC = PMMIN bits = “1” 
→
 “0” 
(12) Off the bass boost: BST1-0 bits = “00” 
(13) Disable the path of “DAC 
→
 HP-Amp”: DACH bit = “1” 
→
 “0”