ak4647 AKM Semiconductor, Inc., ak4647 Datasheet - Page 67

• Manufacturer Part Number: ak4647
• Description: Stereo Codec With Mic/hp-amp
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
MS0566-E-00
Headphone-amp Output
<Example>
At first, clocks should be supplied according to “Clock Set Up” sequence.
(1) Set up a sampling frequency (FS3-0 bits). When the AK4647 is PLL mode, DAC and Headphone-Amp should
(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 input digital volume (Addr: 09H and 0CH)
(5) Set up the output digital volume (Addr: 0AH and 0DH)
(6) Power up DAC and MIN-Amp: PMDAC = PMMIN bits = “0” → “1”
(7) Power up headphone-amp: PMHPL = PMHPR bits = “0” → “1”
(8) Rise up the common voltage of headphone-amp: HPMTN bit = “0” → “1”
(9) Fall down the common voltage of headphone-amp: HPMTN bit = “1” → “0”
(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”
be powered-up in consideration of PLL lock time after a sampling frequency is changed.
When PMADL = PMADR bits = “0”, IVL7-0 and IVR7-0 bits should be set to “91H”(0dB).
(Addr:05H, D5&D2-0)
(Addr:09H&0CH, D7-0)
(Addr:0AH&0DH, D7-0)
PMHPL/R bits
DVL/R7-0 bits
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.
The DAC enters an initialization cycle that starts when the PMDAC bit is changed from “0” to “1” at PMADL
and PMADR bits are “0”. 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 PMADL or
PMADR bit is “1”, the DAC does not require an initialization cycle. When ALC bit is “1”, ALC is disable
(ALC gain is set by IVL/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 IVL/R7-0 bits.
Output voltage of headphone-amp is still HVSS.
The rise time depends on HVDD and the capacitor value connected with the MUTET pin. When HVDD=3.3V
and the capacitor value is 1.0μF, the time constant is
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
(Addr:0EH, D3-2)
IVL/R7-0 bits
(Addr:01H, D5-4)
The fall time depends on HVDD and the capacitor value connected with the MUTET pin. When HVDD=3.3V
and the capacitor value is 1.0μF, the time constant is
(Addr:0FH, D0)
(Addr:01H, D6)
BST1-0 bits
(Addr:00H, D2)
(Addr:00H, D5)
HPL/R pins
PMDAC bit
HPMTN bit
DACH bit
PMBP bit
FS3-0 bits
0,000
E1H
18H
00
(1)
Figure 52. Headphone-Amp Output Sequence
(3)
(2)
(4)
(5)
(6)
(7)
(8)
Normal Output
10
1,111
τ
- 67 -
f
that the common voltage goes to GND.
91H
28H
τ
τ
r
f
= 100ms(typ), 250ms(max).
(9)
= 100ms(typ), 250ms(max).
(10)
(11)
(12)
00
(13)
Example:
PLL, Master Mode
Audio I/F Format :MSB justified (ADC & DAC)
Sampling Frequency: 44.1kHz
Digital Volume: −8dB
Bass Boost level : Middle
(1) Addr:05H, Data:27H
(2) Addr:0FH, Data:09H
(5) Addr:0AH&0DH, Data:28H
(6) Addr:00H, Data:64H
(7) Addr:01H, Data:39H
(8) Addr:01H, Data:79H
(9) Addr:01H, Data:39H
(4) Addr:09H&0CH, Data:91H
(10) Addr:01H, Data:09H
(12) Addr:0EH, Data:11H
(13) Addr:0FH, Data:08H
(3) Addr:0EH, Data:19H
(11) Addr:00H, Data:40H
Playback
[AK4647]
2006/11