AK4950 Datasheet, PDF (55/106 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP & mini DSP

[AK4950]
■ Output Digital Volume (Manual Mode)
The ALC block becomes output digital volume (manual mode) by setting ALC bit to “0” when PMPFIL = PMDAC bits
= “1” and ADCPF bit is “0”. The output digital volume gain is set by the OVL7-0 bit and the OVR7-0 bit (Table 38).
When the OVOLC bit = “1”, the OVL7-0 bits control both L and R channel volume levels. When the OVOLC bit = “0”,
the OVL7-0 bits control L channel volume level and the OVR7-0 bits control R channel volume level. The volume change
is executed via soft transition. The transition time between set values is 10ms@fs =44.1kHz. When changing ADCPF bit,
the volume value is changed to OVL/R(IVL/R) from IVL/R(OVL/R). The switching noise can be reduced by setting into
soft mute sate (SMUTE bit = “1”) before changing ADCPF bit.
OVL7-0 bits
OVR7-0 bits
GAIN [dB]
Step
F1H
+36.0
F0H
+35.625
EFH
+35.25
:
:
0.375dB
92H
+0.375
91H
0.0
90H
-0.375
:
:
2H
-53.625
1H
-54.0
0H
MUTE
Table 38. Output Digital Volume Setting
(default)
■ Output Digital Volume 2
The volume of both L and R channels are controlled together by the DVL7-0. Setting values are shown in Table 39. The
volume change is executed via soft transition. It can be changed during ALC operation. The transition time between set
values is 10ms@fs =44.1kHz.
DVOL7-0 bits GAIN [dB]
Step
F1H
+18.0
F0H
+17.625
EFH
+17.25
:
:
0.375dB
92H
+0.375
91H
0.0
90H
-0.375
:
:
2H
-71.625
1H
-72.0
0H
MUTE
Table 39. Output Digital Volume2 Setting
(default)
MS1320-E-00
- 55 -
2011/10