AK4955 Datasheet, PDF (54/117 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP/ LDO & DSP

[AK4955]
■ Output Digital Volume 2
The AK4955 has a digital output volume (256 levels, 0.5dB step, Mute). The volume is included in front of a DAC block.
The input data of DAC is changed from +12 to –115dB or MUTE. When DVOLC bit = “1”, the DVL7-0 bits control both
Lch and Rch volume levels together. When DVOLC bit = “0”, Lch and Rch volume levels can be controlled
independently by DVL7-0 bits and DVR7-0 bits. This volume has soft transition function. Therefore no switching noise
occurs during the transition. The DVTM bit set the transition time between set values of DVL7-0 and DVR7-0 bits (from
00H to FFH) as either 256/fs or 1024/fs (Table 42). When DVTM bit = “0”, it takes 1024/fs (21.3ms@fs=48kHz) from
00H (+12dB) to FFH (MUTE).
DVL7-0 bits
DVR7-0 bits
Gain
Step
00H
+12.0dB
01H
+11.5dB
02H
+11.0dB
:
:
0.5dB
18H
0dB
(default)
:
FDH
−114.5dB
FEH
−115.0dB
FFH
Mute (− ∞)
Table 41. Output Digital Volume2 Setting
DVTM bit Transition Time between DVL/R7-0 bits = 00H and FFH
Setting
fs=8kHz
fs=48kHz
0
1024/fs
128ms
21.3ms
(default)
1
256/fs
32ms
5.3ms
Table 42. Transition Time Setting of Output Digital Volume2
MS1343-E-00
- 54 -
2011/12