ASAHI KASEI
[AK4644]
Digital Output Volume
The AK4644 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 40). 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
00H
01H
02H
:
Gain
+12.0dB
+11.5dB
+11.0dB
:
18H
:
0dB
:
Default
FDH
FEH
FFH
−114.5dB
−115.0dB
MUTE (−∞)
Table 39. Digital Volume Code Table
Transition time between DVL/R7-0 bits = 00H and FFH
DVTM bit
Setting
1061/fs
256/fs
fs=8kHz
133ms
32ms
fs=44.1kHz
24ms
0
1
Default
6ms
Table 40. Transition Time Setting of Digital Output Volume
MS0477-E-01
2006/10
- 49 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
