ak4644 AKM Semiconductor, Inc., ak4644 Datasheet - Page 49

• Manufacturer Part Number: ak4644
• Description: Stereo Codec With Mic/hp/rcv-amp
• Manufacturer: AKM Semiconductor, Inc.

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