AK7746 Datasheet, PDF (58/62 Pages) Asahi Kasei Microsystems – Audio DSP with 5-channel 24-bit ADC and Input Mux

[ASAHI KASEI]
RQ
SCLK
SI
SO
R(x)
B6h
D15 *** D0
D6h
D15 *** D0
Fig.8-32 Example: Control register writing, reading
3) CRC Check
RQ
SCLK
SI
SO
D(x)
10100000 000000A9A8 A7***A1 A0 D15*** D0
Rest of D(x)/G(x)
B6h
R(x)
The rest (D(x)/G(x))=R(x)
Fig.8-33 The rest of D(x)/G(x)=R(x) CRC Check example.
4) Example of the R(x) made from D(x).
Examples
1
2
3
D(X)
D6ABCDh
D2A5A5h
A855557777AAAA0000FFFFh
R(X)
1E51h
0C30h
2297h
[AK7746]
6) ADC high-pass filter
The AK7746 incorporates a digital high-pass filter (HPF) for canceling DC offset in the ADC. The HPF cut-off frequency is
about 1 Hz (fs = 48 kHz). This cut-off frequency is proportional to the sampling frequency (fs).
Cut-off frequency
96kHz
1.86Hz
48kHz
0.93Hz
44.1kHz
0.86Hz
32kHz
0.62Hz
8kHz
0.16Hz
[MS0369-E00]
- 58 -
2004/12