AK4558EN Datasheet, PDF (62/94 Pages) Asahi Kasei Microsystems – 108dB 216kHz 32Bit CODEC with PLL

[AK4558]
■ Digital Attenuator
The AK4558 has a channel-independent digital attenuator (256 levels, 0.5dB steps). Attenuation level of
the DAC can be set by ATL/R 7-0 bits (Table 30). Transition time between set values of ATL/R bits can be
selected by ATS1-0 bits (Table 31). Transition between set values is the soft transition in Mode1/2/3
eliminating switching noise in the transition. Transition between set values is a soft transition of 4080
levels in Mode 0. It takes 4080/fs (85ms@fs=48kHz) from 00H to FFH. If the PDN pin goes to “L”, ATL/R
7-0 bit are initialized to FFH. These bits are also set to FFH when RSTN bit = “0”, and fade to their current
value when RSTN bit returns to “1”.
ATL/R
7-0 bits
Attenuation Level
FFH
0dB
(default)
FEH
0.5dB
FDH
1.0dB
FCH
1.5dB
:
:
03H
126.5dB
01H
127.0dB
00H
MUTE ()
Table 30. Attenuation Level of Digital Attenuator
Mode
0
1
2
3
ATS1
0
0
1
1
ATS0
0
1
0
1
ATT speed
4080/fs
2040/fs
510/fs
255/fs
(default)
Table 31. Transition Time Setting of Digital Attenuator (ATS 1-0 bits)
015004500-E-02
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2015/09