Production Data
WM8750L
DIGITAL FILTER CHARACTERISTICS
The ADC and DAC employ different digital filters. There are 4 types of digital filter, called Type 0, 1, 2
and 3. The performance of Types 0 and 1 is listed in the table below, the responses of all filters is
shown in the proceeding pages.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
0.416fs
+/- 0.05
UNIT
ADC Filter Type 0 (USB Mode, 250fs operation)
Passband
+/- 0.05dB
-6dB
0
0.5fs
Passband Ripple
Stopband
dB
dB
0.584fs
-60
Stopband Attenuation
f > 0.584fs
ADC Filter Type 1 (USB mode, 272fs or Normal mode operation)
Passband
+/- 0.05dB
-6dB
0
0.4535fs
+/- 0.05
0.5fs
Passband Ripple
Stopband
dB
0.5465fs
-60
Stopband Attenuation
f > 0.5465fs
-3dB
dB
Hz
High Pass Filter Corner
Frequency
3.7
-0.5dB
10.4
-0.1dB
21.6
DAC Filter Type 0 (USB mode, 250fs operation)
Passband
+/- 0.03dB
-6dB
0
0.416fs
+/-0.03
0.5fs
Passband Ripple
Stopband
dB
dB
0.584fs
-50
Stopband Attenuation
f > 0.584fs
DAC Filter Type 1 (USB mode, 272fs or Normal mode operation)
Passband
+/- 0.03dB
-6dB
0
0.4535fs
+/- 0.03
0.5fs
Passband Ripple
dB
dB
Stopband
0.5465fs
-50
Stopband Attenuation
Table 47 Digital Filter Characteristics
f > 0.5465fs
DAC FILTERS
ADC FILTERS
Mode
Group Delay
Mode
Group Delay
13/FS
0 (250 USB)
0 (250 USB)
1 (256/272)
11/FS
16/FS
4/FS
1 (256/272)
23/FS
2 (250 USB, 96k mode)
3 (256/272, 88.2/96k mode)
2 (250 USB, 96k mode)
4/FS
3 (256/272, 88.2/96k mode)
3/FS
5/FS
Table 48 ADC/DAC Digital Filters Group Delay
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
PD, Rev 4.4, August 2012
55
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
