WM8983
Product Preview
SELECTABLE HIGH PASS FILTER
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.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
8
7
HPFEN
1
High Pass Filter Enable
0 = disabled
1 = enabled
Select audio mode or application mode
0 = Audio mode (1st order, fc = ~3.7Hz)
1 = Application mode (2nd order, fc =
HPFCUT)
R14
ADC Control
HPFAPP
0
6:4
Table 13 ADC Enable Control
HPFCUT
000
Application mode cut-off frequency
See Table 14 for details.
HPFCUT
[2:0]
SR=101/100
SR=011/010
fs (kHz)
22.05
SR=001/000
44.1
8
11.025
12
16
24
32
48
82
113
141
180
225
281
360
450
563
122
153
156
245
306
392
490
612
82
113
141
180
225
281
360
450
563
122
153
156
245
306
392
490
612
82
113
141
180
225
281
360
450
563
122
153
156
245
306
392
490
612
000
001
010
011
100
101
110
111
102
131
163
204
261
327
408
102
131
163
204
261
327
408
102
131
163
204
261
327
408
Table 14 High Pass Filter Cut-off Frequencies (HPFAPP=1)
Note that the High Pass filter values (when HPFAPP=1) are calculated on the assumption that the
SR register bits are set correctly for the actual sample rate as shown in Table 14.
PP Rev 1.1 August 2005
30
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
