AK4951AEN Datasheet, PDF (57/105 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/HP/SPK-AMP

[AK4951A]
■ Sidetone Digital Volume
The AK4951A has the digital volume control (4 levels, 6dB step) for the programmable filter output.
Table 47. Sidetone Digital Volume
PFVOL1-0 bits
Gain
00
0dB
(default)
01
-6dB
10
-12dB
11
-18dB
■ 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
0
0
0
1
1
0
1
1
(N/A: Not available)
Table 48. DAC Input Selector
DAC Lch Input Signal
DAC Rch Input Signal
SDTI Lch
PFVOL Lch Output
[(SDTI Lch) + (PFVOL Lch)]/2
N/A
SDTI Rch
PFVOL Rch Output
[(SDTI Rch) + (PFVOL Rch)]/2
N/A
(default)
■ DAC Mono/Stereo Mode
Mono mixing outputs are available by setting MONO1-0 bits. Input data from the SDTI pin can be
converted to mono signal [(L+R)/2] and are output from DAC.
MONO1 bit
0
0
1
1
Table 49. Mono/Stereo DAC operation
MONO0 bit
DAC Lch
Output Signal
DAC Rch
Output Signal
0
Lch
Rch
1
Lch
Lch
0
Rch
Rch
1
(Lch+Rch)/2
(Lch+Rch)/2
(default)
■ Output Digital Volume
The AK4951A 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. DVL7-0 bits control
both Lch and Rch volumes together when DVOLC bit = “1” (default). Lch and Rch volumes are set
individually by DVL7-0 and DVR7-0 bits when DVOLC bit = “0”. 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).
016001936-E-00
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2016/03