WM8978 Wolfson Microelectronics Ltd., WM8978 Datasheet - Page 101

• Manufacturer Part Number: WM8978
• Description: The WM8978 is a low power, high quality stereo codec designed for portable applications such as Digital still camera or Digital Camcorde
• Manufacturer: Wolfson Microelectronics Ltd.

Preliminary Technical Data
HIGHPASS FILTER
Figure 49 ADC Highpass Filter Response, HPFAPP=0
Figure 50 ADC Highpass Filter Responses (48kHz),
Figure 52 ADC Highpass Filter Responses (12kHz),
w
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-40
-10
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-5
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10
5
0
10
0
0
0
0
0
5
HPFAPP=1, all cut-off settings shown.
HPFAPP=1, all cut-off settings shown.
200
200
10
15
400
400
Frequency (Hz)
20
Frequency (Hz)
Frequency (Hz)
The WM8978 has a selectable digital highpass filter in the ADC filter path. This filter has two
modes, audio and applications. In audio mode the filter is a 1
3.7Hz.
frequency.
600
600
25
30
In applications mode the filter is a 2
800
800
35
1000
40
1000
45
1200
1200
Figure 51 ADC Highpass Filter Responses (24kHz),
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10
0
0
HPFAPP=1, all cut-off settings shown.
nd
200
order high pass filter with a selectable cut-off
400
Frequency (Hz)
st
order IIR with a cut-off of around
600
PTD Rev 2.6 November 2005
800
1000
WM8978
1200
101