AK4635 Datasheet, PDF (48/81 Pages) Asahi Kasei Microsystems – 16-Bit Mono CODEC with ALC & MIC/SPK/Video-AMP

[AK4635]
3. The Volume at the ALC Operation
The current volume value at the ALC operation is reflected by VOL7-0 bits. It is enable to check the current volume value
by reading the register value of VOL7-0 bits.
This function is available only at the time of 3-wire mode. The volume value at the ALC operation can
not be read in I²C mode.
VOL7-0bits
F1H
F0H
EFH
:
C5H
:
92H
91H
90H
:
2H
1H
0H
GAIN(0dB)
+36.0
+35.625
+35.25
:
+19.5
:
+0.375
0.0
−0.375
:
−53.625
−54.0
MUTE
Table 33. Value of VOL7-0 bits
4. Example of the ALC Operation for Recording Operation
Table 34 shows the examples of the ALC setting for mic recording.
Register Name
LMTH1-0
ZELM
ZTM1-0
WTM2-0
IREF7-0
IVOL7-0
LMAT1-0
LFST
RGAIN1-0
ALC1
FRSL1-0
Comment
fs=8kHz
Data
Operation
Limiter detection Level
01
−4.1dBFS
Limiter zero crossing detection
0
Enable
Zero crossing timeout period
00
16ms
Recovery waiting period
*WTM1-0 bits should be more than or 000
16ms
equal to ZTM1-0 bits
Maximum gain at recovery operation C5H
19.5dB
Gain of IVOL
C5H
19.5dB
Limiter ATT step
00
1step
Fast Limiter Operation
1
ON
Recovery GAIN step
00
1 step
ALC enable
1
Enable
Speed of Fast Recovery
00
4 times
Table 34. Example of the ALC Setting (Recording)
fs=16kHz
Data
Operation
01
−4.1dBFS
0
Enable
01
16ms
001
16ms
C5H
19.5dB
C5H
19.5dB
00
1step
1
ON
00
1 step
1
Enable
00
4times
Rev. 0.6
- 48 -
2007/10