wm8952 Wolfson Microelectronics plc, wm8952 Datasheet - Page 22

• Manufacturer Part Number: wm8952
• Description: Mono Adc With Microphone Pre-amplifier
• Manufacturer: Wolfson Microelectronics plc

WM8952
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SELECTABLE HIGH PASS FILTER
Table 13 ADC Filter Select
Table 14 High Pass Filter Cut-off Frequencies (HPFAPP=1)
A selectable high pass filter is provided. To disable this filter set HPFEN=0. The filter has two
modes controlled by HPFAPP. In Audio Mode (HPFAPP=0) the filter is first order, with a cut-off
frequency of 3.7Hz. In Application Mode (HPFAPP=1) the filter is second order, with a cut-off
frequency selectable via the HPFCUT register. The cut-off frequencies when HPFAPP=1 are shown
in Table 14.
Note that the High Pass filter values (when HPFAPP=1) work on the basis that the SR register bits
are set correctly for the actual sample rate as shown in Table 14.
HPFCUT
000
001
010
011
100
101
110
111
R14
ADC Control
REGISTER
ADDRESS
102
131
163
204
261
327
408
8
82
8
7
6:4
SR=101/100
BIT
11.02
113
141
180
225
281
360
450
563
5
HPFEN
HPFAPP
HPFCUT
LABEL
12
122
153
196
245
306
392
490
612
16
102
131
163
204
261
327
408
82
1
0
000
DEFAULT
SR=011/010
FS (KHZ)
22.0
113
141
180
225
281
360
450
563
5
High Pass Filter Enable
0=disabled
1=enabled
Select audio mode or application mode
0=Audio mode (1
1=Application mode (2
HPFCUT)
Application mode cut-off frequency
See Table 14 for details.
24
122
153
196
245
306
392
490
612
32
102
131
163
204
261
327
408
82
PP, Rev 3.0, December 2008
DESCRIPTION
SR=001/000
st
44.1
order, fc = ~3.7Hz)
113
141
180
225
281
360
450
563
nd
order, fc =
Pre Production
48
122
153
196
245
306
392
490
612
22