WM8731 / WM8731L
Production Data
DESCRIPTION
Activate Interface
REGISTER
ADDRESS
BIT
LABEL
ACTIVE
DEFAULT
0001001
0
0
Active Control
1 = Active
0 = Inactive
Reset Register
0001111
8:0
RESET
not reset
Reset Register
Writing 00000000 to register resets
device
Table 30 Register Map Description
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
UNIT
ADC Filter Type 0 (USB Mode, 250fs operation)
Passband
+/- 0.05dB
0
0.416fs
+/- 0.05
-6dB
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
0
0.416fs
+/-0.03
-6dB
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 31 Digital Filter Characteristics
PD, Rev 4.8, April 2009
54
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
