WM8731 Wolfson Microelectronics Ltd., WM8731 Datasheet - Page 51

• Manufacturer Part Number: WM8731
• Description: WM8731 : Low Power Audio Codec With Integrated Headphone Driver
• Manufacturer: Wolfson Microelectronics Ltd.

WM8731
DIGITAL FILTER CHARACTERISTICS
Table 30 Digital Filter Characteristics
TERMINOLOGY
1.
2.
ADC Filter Type 0 (USB Mode, 250fs operation)
Passband
Passband Ripple
Stopband
Stopband Attenuation
ADC Filter Type 1 (USB mode, 272fs or Normal mode operation)
Passband
Passband Ripple
Stopband
Stopband Attenuation
High Pass Filter Corner
Frequency
DAC Filter Type 0 (USB mode, 250fs operation)
Passband
Passband Ripple
Stopband
Stopband Attenuation
DAC Filter Type 1 (USB mode, 272fs or Normal mode operation)
Passband
Passband Ripple
Stopband
Stopband Attenuation
Stop Band Attenuation (dB) - the degree to which the frequency spectrum is attenuated (outside audio band)
Pass-band Ripple – any variation of the frequency response in the pass-band region
PARAMETER
Table 29 Register Map Description
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.
0001001
Active Control
0001111
Reset Register
REGISTER
ADDRESS
TEST CONDITIONS
f > 0.5465fs
f > 0.5465fs
f > 0.584fs
f > 0.584fs
+/- 0.05dB
+/- 0.05dB
+/- 0.03dB
+/- 0.03dB
-0.5dB
-0.1dB
-6dB
-6dB
-3dB
-6dB
-6dB
0
8:0
BIT
ACTIVE
RESET
LABEL
0.5465fs
0.5465fs
0.584fs
0.584fs
MIN
-60
-60
-50
-50
0
0
0
0
0
not reset
DEFAULT
0.5fs
0.5fs
0.5fs
0.5fs
TYP
10.4
21.6
3.7
Activate Interface
1 = Active
0 = Inactive
Reset Register
Writing 00000000 to register resets
device
0.4535fs
0.4535fs
+/- 0.05
+/- 0.05
+/- 0.03
0.416fs
0.416fs
+/-0.03
MAX
DESCRIPTION
AI Rev 2.3 August 2001
Advanced Information
UNIT
dB
dB
dB
dB
Hz
dB
dB
dB
dB
51