AK4589_1 Datasheet, PDF (34/76 Pages) Asahi Kasei Microsystems – 2/8-Channel Audio CODEC with DIR

ASAHI KASEI
[AK4589]
Digital Attenuator
The AK4589 has channel-independent digital attenuator (128 levels, 0.5dB step). Attenuation level of each channel can
be set by each ATT7-0 bits (Table 15).
ATT7-0 Attenuation Level
00H
0dB
Default
01H
-0.5dB
02H
-1.0dB
:
:
7DH
-62.5dB
7EH
-63dB
7FH
MUTE (-∞)
:
FEH
MUTE (-∞)
FFH
MUTE (-∞)
Table 15. Attenuation level of digital attenuator
Transition time between set values of ATT7-0 bits can be selected by ATS1-0 bits (Table 16). Transition between set
values is the 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 16. 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) in mode 0. If PDN pin goes to “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.
MS0339-E-00
- 34 -
2004/09