AK4695 Datasheet, PDF (44/107 Pages) Asahi Kasei Microsystems – 24bit 4ch CODEC with MIC/HP/SPK/LINE-AMP

[AK4695]
■ Input Digital Volume (Manual Mode)
The input digital volume becomes manual mode by setting ALC bit = “0”. This mode is suitable in the cases shown below.
1. After exiting reset state, when setting up the registers for ALC operation (such as LMTH bit and etc.)
2. When changing registers for ALC operation (Limiter period, Recovery period and etc.) due to sampling
frequency change.
3. When IVOL is used as a manual volume control.
IV07-0, IV17-0, IV27-0 and IV37-0 bits set the gain of the digital input volume (Table 31). Ch0, Ch1, Ch2 and Ch3
volumes are set individually by IV07-0, IV17-0, IV27-0 and IV37-0 bits, respectively. The volume change between set
values are executed by soft transition in 0.09375dB/fs. Therefore no switching noise occurs during the transition. It takes
960/fs (20ms@fs=48kHz) from F0H(+54dB) to 00H(MUTE).
IV07-0 bits
IV17-0 bits
IV27-0 bits
GAIN [dB]
Step
IV37-0 bits
F0H
+54.0
EFH
+53.625
EEH
+53.25
:
:
B0H
+30.0
:
61H
:
+0.375
0.375 dB
60H
0.0
5FH
–0.375
:
:
02H
–35.25
01H
–35.625
00H
MUTE
Table 31. Input Digital Volume Setting
(default)
If IV07-0, IV17-0, IV27-0 or IV37-0 bits are written during PMDSP bit or PMPFIL3-0 bits = “0”, IVOL operation starts
with the written values after PMPFIL3/2/1/0 bit is changed to “1” while PMDSP bit = “1”.
MS1463-E-01
- 44 -
2014/12