WM8971L_05 Datasheet, PDF (55/61 Pages) Wolfson Microelectronics plc – Stereo CODEC for Portable Audio Applications

Production Data
0
0.4
0.3
-2
0.2
0.1
-4
0
-6
-0.1
-0.2
-8
-0.3
-10
0
5000
10000
Frequency (Fs)
15000
20000
-0.4
0
5000
10000
Frequency (Fs)
Figure 47 De-emphasis Frequency Response (44.1kHz)
0
Figure 48 De-emphasis Error (44.1kHz)
0.4
0.3
-2
0.2
0.1
-4
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-6
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-8
-0.3
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Frequency (Fs)
15000
20000
-0.4
0
5000
10000
Frequency (Fs)
Figure 49 De-emphasis Frequency Response (48kHz)
Figure 50 De-emphasis Error (48kHz)
WM8971L
15000
20000
15000
20000
HIGHPASS FILTER
The WM8971L has a selectable digital highpass filter in the ADC filter path to remove DC offsets. The filter response is
characterised by the following polynomial:
H(z) =
1 - z^-1
1 - 0.9995z^-1
0
-5
-10
-15
0
0.0005
0.001
0.0015
Frequency (Fs)
Figure 51 ADC Highpass Filter Response
0.002
w
PD Rev 4.1 August 2005
55