AK4955 Datasheet, PDF (42/117 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP/ LDO & DSP

[AK4955]
■ Digital HPF1
A digital High Pass Filter (HPF) is integrated for DC offset cancellation of the ADC input. The cut-off frequencies of the
HPF1 are set by HPFC1-0 bits (Table 25). It is proportional to the sampling frequency (fs) and the default value is 3.7Hz
(@fs = 48kHz). HPFAD bit controls the ON/OFF of the HPF1 (HPF ON is recommended).
HPFC1 bit
0
0
1
1
HPFC0 bit
fs=48kHz
fc
fs=22.05kHz
0
3.7Hz
1.7Hz
1
14.8Hz
6.8Hz
0
118.4Hz
54.4Hz
1
236.8Hz
108.8Hz
Table 25. HPF1 Cut-off Frequency
fs=8kHz
0.62Hz
2.47Hz
19.7Hz
39.5Hz
(default)
MS1343-E-00
- 42 -
2011/12