AK4627 Datasheet, PDF (24/46 Pages) Asahi Kasei Microsystems – High Performance Multi-channel Audio CODEC

[AK4627]
■ Digital Attenuator
The AK4627 has channel-independent digital attenuator (128 levels, 0.5dB step). Attenuation level of each channel can
be set by each ATT7-0 bits (Table 12).
ATT7-0
00H
01H
02H
:
7DH
7EH
7FH
FEH
FFH
Attenuation Level
0dB
-0.5dB
-1.0dB
:
-62.5dB
-63dB
MUTE (-∞)
:
MUTE (-∞)
MUTE (-∞)
(default)
Table 12. Attenuation level of digital attenuator
Transition time between set values of ATT7-0 bits can be selected by ATS1-0 bits (Table 13). Transition between set
values is soft transition. Therefore, the switching noise does not occur in the transition.
Mode
0
1
2
3
ATS1
0
0
1
1
ATS0
0
1
0
1
ATT speed
1792/fs
896/fs
256/fs
256/fs
(default)
Table 13. Transition time between set values of ATT7-0 bits
The transition between set values is soft transition of 1792 levels in mode 0. It takes 1792/fs (37.3ms@fs=48kHz) from
00H(0dB) to 7FH(MUTE). When the PDN pin becomes “L”, the ATTs are initialized to 00H. The ATTs are 00H when
RSTN bit= “0”. When RSTN bit return to “1”, the ATTs fade to their current value.
Note: The attenuation level is calculated in 11bit accuracy.
MS1278-E-02
- 24 -
2012/03