AK4492ECB Datasheet, PDF (38/101 Pages) Asahi Kasei Microsystems – Quality Oriented 32-Bit 2ch DAC

[AK4492]
■ D/A Conversion Mode (PCM Mode, DSD Mode, EXDP Mode)
The AK4492 can perform D/A conversion for either PCM data or DSD data. When PCM mode, PCM data
can be input from the BICK, LRCK and SDATA pins. When DSD mode, DSD data can be input from the
A3, B1 and B2 pins if DSDPATH bit = “0” and DSD data can be input from the J1, H1, and G1 pins if
DSDPATH bit = “1”. The DP bit controls PCM/DSD mode. The AK4492 must be reset by setting RSTN bit
= “0” when PCM/DSD mode is changed by DP bit or when DSD signal input pins are changed by
DSDPATH bit. It takes about 2 ~ 3/fs to change the mode. Wait 4/fs or more to change RSTN bit after
changing these settings.
External digital filter I/F can be selected by setting DP bit = “0” and EXDF bit = “1”. When using an external
digital filter (EXDF I/F mode), data is input to each MCLK, BCK, WCK, DINL and DINR pin. EXDF bit
controls the modes. When switching internal and external digital filters by EXDF bit, the AK4492 must be
reset by RSTN bit. A Digital filter switching takes 2~3k/fs. The AK4492 is in DSD mode when DP bit = “1”
and EXDF bit “1”.
DP bit
0
(default)
1
1
EXDF bit
0
(default)
x
Table 4. PCM/DSD/EXDF Mode Control
DSDPATH
bit
D/A
Conv.
Mode
Pin Assignment
J1 pin H1 pin G1 pin A3 pin
B1 pin
B2 pin
x
PCM BICK SDATA LRCK Not Use Not Use Not Use
0
(default)
DSD Not Use Not Use Not Use DCLK DSDL DSDR
x
1
DSD DCLK DSDL DSDR Not Use Not Use Not Use
0
1
(x: Do not care)
x
EXDF BCK DINL DINR Not Use Not Use Not Use
■ D/A Conversion Mode Switching Timing
Figure 21 and Figure 22 show switching timing of PCM/EXDF and DSD modes. To prevent noise caused
by excessive input, DSD signal should be input 4/fs after setting RSTN bit = “0” until the device is
completely reset internally when the conversion mode is changed to DSD mode from PCM/ESDF mode.
DSD signal should be stopped 4/fs after setting RSTN bit = “0”until the device is completely reset
internally when the conversion mode is changed to PCM/EXDE from DSD mode.
RSTN bit
D/A Mode
4/fs
PCM or EXDF Mode
D/A Data
PCM or EXDF Data
DSD Mode
0
DSD Data
Figure 21. D/A Mode Switching Timing (from PCM or EXDF to DSD)
016011073-E-00
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2016/12