[AK4493]
017012230-E-00
2017/12
- 56 -
■
Output Volume (PCM, DSD and EXDF Modes; Register Control Mode only)
The AK4493 includes channel independent digital output volumes (ATTL/R) with 256 levels at 0.5dB step
including MUTE. When changing output levels, it is executed in soft transition, thus no switching noise
occurs during these transitions. It can attenuate the input data from 0dB to -127dB and MUTE when
assuming the output signal level is 0dB when ATTL/R[7:0] bits =
“FFH”.
Table 29. Attenuation Level of Digital Attenuator
ATTL/R[7:0]bits
(register 03-04H)
Attenuation Level
FFH
+0dB
(default)
FEH
-0.5dB
FDH
-1.0dB
:
:
:
:
02H
-126.5dB
01H
-127.0dB
00H
MUTE (-
∞)
The transition time of digital output volume is set by ATS[1:0] bits (
). When changing output
levels between Mode0-3, it is executed in soft transition thus no switching noise occurs during these
transitions. Register setting values will be kept even switching the PCM and DSD modes.
Table 30. Transition Time between Set Values of ATTL/R[7:0] bits
Mode
ATS1
ATS0
ATT speed
EXDF bit=
“0”,
DP bit=
“0”
EXDF bit=
“1”
DP bit=
“0”
DP bit=
“1”
0
0
0
4080/fs
4080*WCK cycle
4080/(2*fs)
(default)
1
0
1
2040/fs
2040*WCK cycle
2040/(2*fs)
2
1
0
510/fs
510*WCK cycle
510/(2*fs)
3
1
1
255/fs
255*WCK cycle
255/(2*fs)
It takes
4080/fs (92.5ms @fs=44.1kHz) from
“FFH” (0dB) to “00H” (MUTE) in Mode 0. The attenuation
level is initialized to
“FFH” (0dB) by setting the PDN pin = “L”.
If the volume is changed during reset period, the output volume will become a setting value after releasing
the reset. It will change to a setting value immediately if the volume is changed within 5/fs after releasing
reset.
