AK4691 Datasheet, PDF (46/80 Pages) Asahi Kasei Microsystems – 4ch ADC + 2ch DAC with MIC/HP/SPK-AMP

[AK4691]
■ Input Digital Volume (Manual Mode)
The input digital volume becomes a manual mode when ALC bit is “0”. This mode is for the case shown below. The
volume setting is common to ADC1 and ADC2 and has two tables that are LINE and MIC.
1. After exiting reset state, when setting up the registers for the ALC operation (ZTM1-0, LMTH1-0 and etc)
2. When the registers for the ALC operation (Limiter period, Recovery period and etc) are changed.
For example; when the change of the sampling frequency.
3. When IVOL is used as a manual volume.
IVL7-0 and IVR7-0 bits set the gain of the volume control (Table 36). The IVOL value is changed at zero crossing or
timeout. Zero crossing timeout period is set by ZTM1-0 bits. If IVL7-0 or IVR7-0 bits are written during PMADC1 =
PMADC2 = PMDAC bits = “0”, IVOL operation starts with the written values at the end of the ADC/DAC initialization
cycle after PMADC1, PMADC2, or PMDAC bit is changed to “1”.
Even if the path is switched from recording to playback, the register setting of IVL/R remains. Therefore, IVL7-0 and
IVR7-0 bits should be set to “91H” (0dB) at GSEL bit = “0”.
IVL7-0 bits
IVR7-0 bits
GAIN(dB)
MIC
LINE
(GSEL bit = “0”) (GSEL bit = “1”)
F1H
+36.0
+6.0
F0H
+35.625
+5.625
EFH
+35.25
+5.25
:
E2H
E1H
E0H
DFH
:
+30.375
+30.0
+29.625
+29.25
:
+0.375
0
-0.375
-0.75
(default)
:
:
:
04H
-52.875
-82.875
03H
-53.25
-83.25
02H
-53.625
-83.625
01H
-54.0
-84.0
00H
MUTE
MUTE
Table 36. Input Digital Volume Setting
MS0672-E-00
- 46 -
2007/11