ak4648 AKM Semiconductor, Inc., ak4648 Datasheet - Page 57

• Manufacturer Part Number: ak4648
• Description: Stereo Codec With Mic/hp/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

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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).
MS0625-E-01
Digital Output Volume
DVTM bit
0
1
DVL/R7-0
Table 39. Transition Time Setting of Digital Output Volume
FDH
FEH
FFH
00H
01H
02H
18H
:
:
Transition time between DVL/R7-0 bits = 00H and FFH
1061/fs
Setting
Table 38. Digital Volume Code Table
256/fs
MUTE ( −∞ )
− 114.5dB
− 115.0dB
+12.0dB
+11.5dB
+11.0dB
Gain
0dB
:
:
- 57 -
fs=8kHz
133ms
32ms
0.5dB
Step
fs=44.1kHz
(default)
24ms
6ms
(default)
[AK4648]
2007/06