AK4637EN Datasheet, PDF (57/96 Pages) Asahi Kasei Microsystems – 24bit Mono CODEC with MIC/SPK-AMP

[AK4637]
■ Sidetone Digital Volume
The AK4637 has the digital volume control (4 levels, 6dB step) for the programmable filter output.
PFVOL1-0 bits
Gain
00
0dB
(default)
01
-6dB
10
-12dB
11
-18dB
Table 41. Sidetone Digital Volume
■ DAC Input Selector
PFDAC1-0 bits select the signal of the DAC input or set the data mixing for each channel data.
PFDAC1 PFDAC0
bit
bit
DAC Input Signal
0
0
SDTI
(default)
0
1
PFVOL Output
1
0
(SDTI + PFVOL) / 2
1
1
N/A
Table 42. DAC Input Selector (N/A: Not available)
■ Output Digital Volume
The AK4637 has a digital output volume (205 levels, 0.5dB step, Mute). The volume is included in front of
a DAC block. The input data of DAC is changed from +12 to –89.5dB or MUTE. DVOL7-0 bits control
volume. This volume has soft transition function. In automatic attenuation, the volume is attenuated by
soft transition in 204/fs or 816/fs to reduce switching noises. When DVTM bit = “0”, it takes 816/fs
(17.0ms@fs=48kHz) from 00H (+12dB) to CCH (MUTE).
DVOL7-0 bits
Gain
Step
00H
+12.0dB
01H
+11.5dB
02H
+11.0dB
:
18H
:
0dB
0.5dB _(default)
:
CAH
89.0dB
CBH
89.5dB
CCH~FFH Mute ( )
Table 43. Output Digital Volume Setting
Transition Time between
DVTM bit
DVL/R7-0 bits = 00H and CCH
Setting
fs=8kHz
fs=48kHz
0
816/fs
102ms
17.0ms
(default)
1
204/fs
25.5ms
4.3ms
Table 44. Transition Time Setting of Output Digital Volume
015010680-E-00
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2015/09