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3.2.3.6SignalProcessing2
DACOversamplingControlOptions
TheSignalProcessing2FunctionmenutabisshowninFigure3-17.
Figure3-17.SignalProcessing2FunctionMenuTab
DACOversamplingControlOptions
SelecttheDACoversamplingcontrolmenutodeterminetheDACoversamplingrate.Theoversampling
controlcanbesettoeither128f
S
orarangeof192f
S
,256f
S
,and384f
S
.
TheDACoversamplingraterange(for192f
S
,256f
S
,and384f
S
)willbeselectedwhenthesampling
frequencyofinputdataislowerthan24kHz.Thisoversamplingratemovestheout-of-bandnoisecaused
bythedelta-sigmamodulatortoahigherfrequencydomain.
ZeroCrossControlOptions
SelecttheZerocrosscontroltoenablethezerocrossingfunction.Whenzerocrossingisenabled,digital
attenuationandtheanalogvolumelevelchangeatthezerocrossingpointtoavoidanaudiblezipper
noise.
De-EmphasisFilterOptions
SelecttheDe-emphasisfilteroptionmenutoenablethede-emphasisfilter.De-emphasiscanbedisabled
orenabledforanappropriatesamplingfrequency.
High-PassFilterOptions
ChoosetheHighPassFiltermenutodeterminethecenterfrequency(f
c
)oftheincominganalogsignal
inputstotheADC.
ThecutofffrequencyoftheADChigh-passfilterisprovidedasasamplingfrequencyof48kHzinthisdrop
downmenu,sothatthecutoffwillbescaleddowntothecorrespondingvaluewhensamplingfrequencies
otherthan48kHz(suchas16kHzor22.05kHz)areused.
TheADChigh-passfiltercutofffrequencycanbesetfromthisoption.
Set-UpGuide 34SBAU127–July2007
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