[AK4675]
■ Digital Output Volume
The AK4675 has a digital output volume (256 levels, 0.5dB step, Mute). The volume can be set by the OVL7-0 and
OVR7-0 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 OVOLC bit = “1”, the OVL7-0 bits control both Lch and Rch attenuation levels. When the OVOLC bit
= “0”, the OVL7-0 bits control Lch level and OVR7-0 bits control Rch level. This volume has a soft transition function.
The OVTM bit sets the transition time between set values of OVL/R7-0 bits as either 1061/fs or 256/fs (Table 37). When
OVTM 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).
OVL/R7-0
00H
01H
02H
:
Gain
+12.0dB
+11.5dB
+11.0dB
:
Step
0.5dB
18H
:
0dB
:
(default)
FDH
FEH
FFH
−114.5dB
−115.0dB
MUTE (−∞)
Table 36. Digital Volume Code Table
Transition time between DVL/R7-0 bits = 00H and FFH
OVTM bit
Setting
1061/fs
256/fs
fs=8kHz
133ms
32ms
fs=44.1kHz
24ms
0
1
(default)
6ms
Table 37. Transition Time Setting of Digital Output Volume
MS0963-E-00
2008/05
- 83 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
