WM8711L
Production Data
DIGITAL FILTER CHARACTERISTICS
The 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
+/-0.03
UNIT
DAC Filter Type 0 (USB mode, 250fs operation)
Passband
+/- 0.03dB
-6dB
0
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
Stopband
dB
dB
0.5465fs
-50
Stopband Attenuation
f > 0.5465fs
Table 24 Digital Filter Characteristics
DAC FILTERS
Mode
Group Delay
11/FS
0
1
2
3
18/FS
5/FS
5/FS
Table 25 DAC Digital Filters Group Delay
DAC FILTER RESPONSES
0.04
0.03
0.02
0.01
0
0
-20
-40
-60
-0.01
-0.02
-0.03
-0.04
-80
-100
0
0.5
1
1.5
2
2.5
3
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Frequency (Fs)
Frequency (Fs)
Figure 22 DAC Digital Filter Frequency Response–Type 0
Figure 23 DAC Digital Filter Ripple–Type 0
PD, Rev 4.5, August 2011
38
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
