[AK4634]
■ Output Digital volume (Manual mode)
When ADCPF bit = “0” and ALC2 bit = “0”, ALC block become an output digital volume (manual mode). The digital
volume’s gain is set by OVOL7-0 bits as shown in Table 23. The OVOL7-0 bits value are reflected to this output volume
at zero cross or zero cross time out. The zero crossing timeout period is set by ZTM1-0 bits.
OVOL7-0bits
GAIN(0dB)
Step
F1H
F0H
EFH
:
92H
91H
90H
:
+36.0
+35.625
+35.25
:
+0.375
0.0
0.375dB
(default)
-0.375
:
2H
1H
-53.625
-54.0
MUTE
0H
Table 23 Output Digital Volume Setting
When writing to the OVOL7-0 bits continually, the control register should be written by an interval more than zero
crossing timeout. If not, zero crossing counter could be reset at each time and volume is not be changed. However, It
could be ignored when writing a same register value as the last time. At this time, zero crossing counter is not reset, so it
can be written by an interval less than zero crossing timeout.
■ Output Digital Volume2
The AK4634 has 4 steps output volume in addition to the volume setting by OVOL7-0 bits. This volume is set by
DATT1-0 bits as shown in Table 24.
DATT1-0bits
GAIN(0dB)
Step
0H
1H
2H
3H
0.0
-6.0
-12.0
-18.1
(default)
6.0dB
Table 24. Output Digital Volume2 Setting
Rev. 0.5
2007/10
- 42 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
