[AK4480]
■ D/A Conversion Mode Switching Timing
RSTN bit
≥4/fs
D/A Mode
D/A Data
PCM Mode
DSD Mode
≥0
PCM Data
DSD Data
Figure 10. D/A Mode Switching Timing (PCM to DSD)
RSTN bit
D/A Mode
DSD Mode
PCM Mode
≥4/fs
D/A Data
DSD Data
PCM Data
Figure 11. D/A Mode Switching Timing (DSD to PCM)
Note. The signal range is identified as 25% ~ 75% duty ratios in DSD mode. DSD signal must not go beyond this duty
range at the SACD format book (Scarlet Book).
■ De-emphasis Filter
A digital de-emphasis filter is available for 32kHz, 44.1kHz or 48kHz sampling rates (tc = 50/15µs). It is enabled and
disabled with DEM1-0 pins or DEM1-0 bits. In case of 256fs/384fs and 128fs/192fs, the digital de-emphasis filter is
always off. When DSD mode, DEM1-0 bits are ignored. The setting value is held even if PCM mode and DSD mode are
switched.
DEM1
DEM0
Mode
44.1kHz
OFF
48kHz
32kHz
0
0
1
1
0
1
0
1
(default)
Table 17. De-emphasis Control
■ Output Volume (PCM and DSD)
The AK4480 includes channel independent digital output volume control (ATT) with 255 levels at linear step including
MUTE. This volume control is in front of the DAC and it can attenuate the input data from 0dB to –48dB and mute. When
changing output levels, transitions are executed in soft change; thus no switching noise occurs during these transitions.
Transition Time
Sampling Speed
1 Level
4LRCK
8LRCK
16LRCK
4LRCK
255 to 0
Normal Speed Mode
Double Speed Mode
Quad Speed Mode
DSD Mode
1020LRCK
2040LRCK
4080LRCK
1020LRCK
Table 18. ATT Transition Time
MS1146-E-03
2012/01
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AKM [ ASAHI KASEI MICROSYSTEMS ]
