[AK4493]
017012230-E-00
2017/12
- 44 -
[3] External Digital Filter Mode (EXDF Mode; Register Control mode only)
The external clocks that are required in EXDF mode are MCLK, BCK and WCK. The BCK and MCLK
clocks must be the same frequency and continuous, not burst mode. BCK and MCLK frequencies for
each sampling speed are shown in
. ECS bit selects WCK frequency from 384kHz and 768kHz.
All circuits except control registers, bias generation circuit and internal LDO (if LDOE pin =
“H”) of the
AK4493 are automatically placed in power-down state when MCLK edge is not detected for more than
1us during normal operation (PDN pin =
“H”), and the analog output becomes Hi-Z state. The
power-down state is released and the AK4493 starts operation by inputting MCLK again. In this case,
register settings are not initialized.
When the reset is released (PDN pin =
“L” → “H”), the AK4493 is in power-down state until MCLK, BCK
and WCK are input.
Table 21. System Clock Example (EXDF Mode)
Sampling
Speed[kHz]
MCLK&BCK [MHz]
ECS
bit
32fs
48fs
64fs
96fs
352.8
11.2896 16.9344 22.5792 33.8688
1
384
12.288
18.432
24.576
36.864
1
Sampling
Speed[kHz]
MCLK&BCK [MHz]
ECS
bit
8fs
16fs
32fs
48fs
705.6
N/A
N/A
22.5792 33.8688
0
(default)
768
N/A
N/A
24.576
36.864
0