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WM8952 Datasheet, PDF (65/72 Pages) Wolfson Microelectronics plc – Mono ADC with Microphone Pre-amplifier
Pre Production
DIGITAL FILTER CHARACTERISTICS
PARAMETER
ADC Filter
Passband
Passband Ripple
Stopband
Stopband Attenuation
Group Delay
ADC High Pass Filter
High Pass Filter Corner
Frequency
TEST CONDITIONS
+/- 0.025dB
-6dB
f > 0.546fs
-3dB
-0.5dB
-0.1dB
Table 48 Digital Filter Characteristics
WM8952
MIN
0
0.546fs
-60
TYP
0.5fs
21/fs
3.7
10.4
21.6
MAX
0.454fs
+/- 0.025
UNIT
dB
dB
Hz
TERMINOLOGY
1. Stop Band Attenuation (dB) – the degree to which the frequency spectrum is attenuated (outside audio band)
2. Pass-band Ripple – any variation of the frequency response in the pass-band region
3. Note that this delay applies only to the filters and does not include additional delays through other digital circuits. See
Table 49 for the total delay.
PARAMETER
Total Delay (ADC analogue
input to digital audio interface
output)
Table 49 Total Group Delay
MIN
28/fs
Notes
1. Wind noise filter is disabled.
TYP
30/fs
MAX
32/fs
UNIT
fs
ADC FILTER RESPONSES
0
-20
-40
-60
-80
-100
-120
0
0.5
1
1.5
2
2.5
3
Frequency (Fs)
0.2
0.15
0.1
0.05
0
-0.05
-0.1
-0.15
-0.2
0
0.1
0.2
0.3
0.4
0.5
Frequency (Fs)
Figure 32 ADC Digital Filter Frequency Response
Figure 33 ADC Digital Filter Ripple
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PP, Rev 3.1, June 2011
65