WM8772
Production Data
ADC FILTER RESPONSES
0.02
0.015
0.01
0
-20
-40
-60
-80
0.005
0
-0.005
-0.01
-0.015
-0.02
0
0.5
1
1.5
2
2.5
3
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Frequency (Fs)
Frequency (Fs)
Figure 5 ADC Digital Filter Frequency Response
Figure 6 ADC Digital Filter Ripple
ADC HIGH PASS FILTER
The WM8772EDS has a selectable digital high pass filter to remove DC offsets. The filter response is characterised by the
following polynomial.
1 − z−1
H(z) =
1 − 0.9995z−1
DIGITAL DE-EMPHASIS CHARACTERISTICS
0
1
0.5
0
-2
-0.5
-1
-4
-6
-1.5
-2
-8
-2.5
-3
-10
0
2
4
6
8
10
12
14
16
0
2
4
6
8
10
12
14
16
Frequency (kHz)
Frequency (kHz)
Figure 7 De-Emphasis Frequency Response (32kHz)
Figure 8 De-Emphasis Error (32KHz)
PD Rev 4.2 October 2005
14
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
