WM8912
Production Data
DAC SLOPING STOPBAND FILTER
Two DAC filter types are available, selected by the register bit DAC_SB_FILT. When operating at
lower sample rates (e.g. during voice communication) it is recommended that the sloping stopband
filter type is selected (DAC_SB_FILT=1) to reduce out-of-band noise which can be audible at low
DAC sample rates. See “Digital Filter Characteristics” for details of DAC filter characteristics.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R33 (21h)
DAC Digital 1
11
DAC_SB_FILT
0
Selects DAC filter characteristics
0 = Normal mode
1 = Sloping stopband mode
Table 21 DAC Sloping Stopband Filter
DAC OVERSAMPLING RATIO (OSR)
The DAC oversampling rate is programmable to allow power consumption versus audio performance
trade-offs. The default oversampling rate is low for reduced power consumption; using the higher
OSR setting improves the DAC signal-to-noise performance.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R33 (21h)
6
DAC_OSR128
0
DAC Oversample Rate Select
0 = Low power (normal OSR)
1 = High performance (double OSR)
DAC Digital 1
Table 22 DAC Oversampling Control
PD, Rev 4.0, September 2010
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