WM8940_07 Datasheet, PDF (78/85 Pages) Wolfson Microelectronics plc – Mono CODEC with Speaker Driver

WM8940
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
DAC Filter
Passband
Passband Ripple
Stopband
Stopband Attenuation
Group Delay
-0.1dB
+/- 0.035dB
-6dB
f > 0.546fs
Table 61 Digital Filter Characteristics
Pre-Production
MIN
0
0.546fs
-60
0
0.546fs
-55
TYP
0.5fs
21/fs
3.7
10.4
21.6
0.5fs
29/fs
MAX
0.454fs
+/- 0.025
UNIT
dB
dB
Hz
0.454fs
+/-0.035
dB
dB
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 62 for the total delay.
PARAMETER
Total Delay (ADC analogue
input to digital audio interface
output)
Total Delay (Audio interface
input to DAC analogue
output)
Table 62 Total Group Delay
MIN
28/fs
33/fs
Notes
1. Wind noise filter is disabled.
TYP
30/fs
35/fs
MAX
32/fs
UNIT
fs
37/fs
fs
w
Pre-Production, Rev 3.0, February 2007
78