AK4497 Datasheet, PDF (35/98 Pages) Asahi Kasei Microsystems – Quality Oriented 32-Bit 2ch DAC

[AK4497]
■ D/A Conversion Mode
The AK4497 can perform D/A conversion for either PCM data or DSD data. The DP bit controls
PCM/DSD mode. When DSD mode, DSD data can be input from the #16, #17 and #19 pins if DSDPATH
bit = “0” and DSD data can be input from the #3, #4, and #5 pins if DSDPATH bit = “1”. The AK4497 must
be reset by setting RSTN bit = “0” when PSM/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 DP or DSDPATH bit setting after setting RSTN bit = “0”.
When the AK4497 is in pin control mode, PCM mode is only available. 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 AK4497 must be reset by RSTN bit. A Digital
filter switching takes 2~3k/fs. The AK4497 is in DSD mode when DP bit = “1” and EXDF bit “1”.
DP bit EXDF bit
0
0
(default) (default)
1
*
1
*
0
1
(*: Do not care)
Table 4. PCM/DSD/EXDF Mode Control
DSDPATH D/A Conv.
Pin Assignment
bit
Mode _{#3 pin #4 pin #5 pin #16 pin}
*
0
(default)
1
*
PCM
DSD
DSD
EXDF
BICK SDATA LRCK Not Use
Not Use Not Use Not Use DCLK
DCLK DSDL DSDR Not Use
BCK DINL DINR Not Use
#17 pin
Not Use
DSDL
Not Use
Not Use
#19 pin
Not Use
DSDR
Not Use
Not Use
■ D/A Conversion Mode Switching Timing
Figure 18 and Figure 19 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 18. D/A Mode Switching Timing (PCM or EXDF to DSD)
Rev. 0.1
- 35 -
2015/11