
ASAHI KASEI
[AK4589]
MS0339-E-00
2004/09
-
34
-
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
01H -0.5dB
02H -1.0dB
: :
7DH -62.5dB
7EH -63dB
7FH
MUTE (-
∞
)
:
FEH
MUTE (-
∞
)
FFH
MUTE (-
∞
)
Default
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 ATS1 ATS0 ATT
speed
0 0 0 1792/fs
1 0 1 896/fs
2 1 0 256/fs
3 1 1 256/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.