WM8734 ETC-unknow, WM8734 Datasheet - Page 36

• Manufacturer Part Number: WM8734
• Description: Stereo Audio Codec
• Manufacturer: ETC-unknow

WM8734
Figure 28 ADC Digital Filter Frequency Response –Type 1
Figure 30 ADC Digital Filter Frequency Response –Type 2
ADC HIGH PASS FILTER
DIGITAL DE-EMPHASIS CHARACTERISTICS
Figure 32 De-Emphasis Frequency Response (32kHz)
w
-100
-20
-40
-60
-80
-10
-10
-2
-4
-6
-8
-2
-4
-6
-8
0
0
0
0
0
0
2000
0.5
5000
4000
1
6000
Frequency (Fs)
Frequency (Fs)
Frequency (Fs)
The WM8734 has a selectable digital high pass filter to remove DC offsets. The filter response is
characterised by the following polynomial.
10000
H(z) =
8000
1.5
10000
1 – 0.9995 z
15000
2
1 – z
12000
-1
2.5
14000
-1
20000
16000
3
Figure 29 ADC Digital Filter Ripple –Type 1
Figure 31 ADC Digital Filter Ripple –Type 2
Figure 33 De-Emphasis Error (32kHz)
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
0.02
0.01
-0.1
-0.2
-0.3
-0.4
-0.1
-0.2
-0.3
-0.4
0.4
0.3
0.2
0.1
0.4
0.3
0.2
0.1
0
0
0
0
0
0
2000
0.05
5000
4000
6000
0.1
Frequency (Fs)
Frequency (Fs)
Frequency (Fs)
10000
8000
0.15
AI Rev 2.2 November 2001
10000
15000
Advanced Information
12000
0.2
14000
20000
16000
0.25
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