AK4648 Datasheet, PDF (57/119 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP/SPK-AMP

[AK4648]
■ Digital Output Volume
The AK4648 has a digital output volume (256 levels, 0.5dB step, Mute). The volume can be set by the DVL7-0 and
DVR7-0 bits. The volume is included in front of a DAC block. The input data of DAC is changed from +12 to –115dB or
MUTE. When the DVOLC bit = “1”, the DVL7-0 bits control both Lch and Rch attenuation levels. When the DVOLC bit
= “0”, the DVL7-0 bits control Lch level and DVR7-0 bits control Rch level. This volume has a soft transition function.
The DVTM bit sets the transition time between set values of DVL/R7-0 bits as either 1061/fs or 256/fs (Table 39). When
DVTM bit = “0”, a soft transition between the set values occurs (1062 levels). It takes 1061/fs (=24ms@fs=44.1kHz)
from 00H (+12dB) to FFH (MUTE).
DVL/R7-0
Gain
Step
00H
+12.0dB
01H
+11.5dB
02H
+11.0dB
:
18H
:
0dB
0.5dB
:
:
FDH
−114.5dB
FEH
−115.0dB
FFH
MUTE (−∞)
Table 38. Digital Volume Code Table
(default)
DVTM bit
Transition time between DVL/R7-0 bits = 00H and FFH
Setting
fs=8kHz
fs=44.1kHz
0
1061/fs
133ms
24ms
1
256/fs
32ms
6ms
Table 39. Transition Time Setting of Digital Output Volume
(default)
MS0625-E-01
- 57 -
2007/06