[AK4679]
■ Digital Output Volume (DATT-A)
The AK4679 has a digital output volume (DATT-A: 128 levels, 0.5dB step, Mute). The volume can be set by the OVL6-0
and OVR6-0 bits. The volume is included in front of a DAC block. The input data of DAC is changed from +6 to –57dB
or MUTE. When the OVOLC bit = “1”, the OVL6-0 bits control both Lch and Rch attenuation levels. When the OVOLC
bit = “0”, the OVL6-0 bits control Lch level and OVR6-0 bits control Rch level. This volume has a soft transition
function. The OVTM bit sets the transition time between set values of OVL/R6-0 bits as either 128/fs or 256/fs (Table
69). When OVTM bit = “1”, a soft transition between the set values occurs (256 levels). It takes 256/fs
(=5.8ms@fs=44.1kHz) from 00H (+6dB) to 7FH (MUTE).
OVL/R6-0 bits
Gain
+6.0dB
+5.5dB
+5.0dB
:
Step
00H
01H
02H
:
0CH
:
0.5dB
0dB
:
(default)
7DH
7EH
7FH
−56.5dB
−57.0dB
MUTE (−∞)
Table 68. Digital Volume A Code Table
Transition time between OVL/R6-0 bits = 00H and 7FH
OVTM bit
Setting
128/fs
256/fs
fs=8kHz
16ms
32ms
fs=44.1kHz
2.9ms
0
1
5.8ms
(default)
Table 69. Transition Time Setting of Digital Output Volume A
MS1402-E-06
2013/02
- 101 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
