ASAHI KASEI
[AK4387]
LRCK
0
1
2
3
23
24
25
31
0
1
2
3
23
24
25
31
0
1
BICK
(64fs)
SDTI
0
1
23 22
23:MSB, 0:LSB
Don’t care
23 22
1
0
Don’t care
23
Lch Data
Figure 4. Mode 3 Timing
Rch Data
De-emphasis Filter
A digital de-emphasis filter is available for 32, 44.1 or 48kHz sampling rates (tc = 50/15µs) and is enabled or disabled
with DEM0 and DEM1. In case of double speed and quad speed mode, the digital de-emphasis filter is always off.
DEM1
DEM0
Mode
0
0
1
1
0
1
0
1
44.1kHz
OFF
Default
48kHz
32kHz
Table 8. De-emphasis Filter Control (Normal Speed Mode)
Output Volume
The AK4387 includes channel independent digital output volumes (ATT) with 256 levels at linear step including MUTE.
These volumes are in front of the DAC and can attenuate the input data from 0dB to –48dB and mute. When changing
levels, transitions are executed via soft changes; thus no switching noise occurs during these transitions. The transition
time of 1 level and all 256 levels is shown in Table 10.
Sampling Speed
Transition Time
1 Level
255 to 0
Normal Speed Mode
Double Speed Mode
Quad Speed Mode
4LRCK
8LRCK
16LRCK
1020LRCK
2040LRCK
4080LRCK
Table 9. ATT Transition Time
MS0429-E-00
2005/09
- 11 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
