WM8753L
Advanced Information
HIGHPASS FILTER
The WM8753 has a selectable digital highpass filter in the ADC filter path to remove DC offsets.
HPMODE[1:0] = 00
The filter response is characterised by the following polynomial:
H(z) =
1 – z-1
1 – 0.9995z-1
5
0
-5
-10
-15
0.0000
0.0005
0.0010
0.0015
0.0020
Frequency (Fs)
Figure 56 ADC Highpass Filter Response, HPMODE[1:0] = 00
HPMODE[1:0] = 01
The filter response is characterised by the following polynomial:
H(z) =
1 – z-1
1 – 0.96875z-1
5
0
-5
-10
-15
-20
-25
0.00
0.01
0.02
0.03
0.04
0.05
Frequency (Fs)
Figure 57 ADC Highpass Filter Response, HPMODE[1:0] = 01
AI Rev 3.1 June 2004
83
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
