Datasheet

Interface#0
Interface#1
PCM2906B
www.ti.com ...........................................................................................................................................................................................SLES227–DECEMBER2008
Interface#0isthecontrolinterface.Alternativesetting#0istheonlypossiblesettingforinterface#0.Alternative
setting#0describesthestandardaudiocontrolinterface.Theaudiocontrolinterfaceconsistsofasingle
terminal.ThePCM2906Bhasthefollowingfiveterminals:
•Inputterminal(IT#1)forisochronous-outstream
•Outputterminal(OT#2)foraudioanalogoutput
•Featureunit(FU#3)forDACdigitalattenuator
•Inputterminal(IT#4)foraudioanaloginput
•Outputterminal(OT#5)forisochronous-instream
Inputterminal#1isdefinedasaUSBstream(terminaltype0x0101).Inputterminal#1canaccepttwo-channel
audiostreamsconsistingofleftandrightchannels.Outputterminal#2isdefinedasaspeaker(terminaltype
0x0301).Inputterminal#4isdefinedasamicrophone(terminaltype0x0201).Outputterminal#5isdefinedasa
USBstream(terminaltype0x0101).Outputterminal#5cangeneratetwo-channelaudiostreamscomposedof
leftandrightchanneldata.Featureunit#3supportsthefollowingsoundcontrolfeatures:
•Volumecontrol
•Mutecontrol
Thebuilt-indigitalvolumecontrollercanbemanipulatedbyanaudio-class-specificrequestfrom0dBto–64dB
in1-dBsteps.Changesaremadebyincrementingordecrementingbyonestep(1dB)forevery1/f
S
timeinterval
untilthevolumelevelhasreachedtherequestedvalue.Eachchannelcanbesetfordifferentvalues.Themaster
volumecontrolisnotsupported.Arequesttothemastervolumeisstalledandignored.Thebuilt-indigitalmute
controllercanbemanipulatedbyaudio-class-specificrequest.Amastermutecontrolrequestisacceptable.A
requesttoanindividualchannelisstalledandignored.
Interface#1istheaudiostreamingdata-outinterface.Interface#1hasthefivealternativesettingslistedin
Table5.Alternativesetting#0isthezero-bandwidthsetting.Allotheralternativesettingsareoperationalsettings.
Table5.Interface#1AlternativeSettings
ALTERNATIVETRANSFERSAMPLINGRATE
SETTINGDATAFORMATMODE(kHz)
00Zerobandwidth
0116-bitStereoTwoscomplement(PCM)Adaptive32,44.1,48
0216-bitMonoTwoscomplement(PCM)Adaptive32,44.1,48
038-bitStereoTwoscomplement(PCM)Adaptive32,44.1,48
048-bitMonoTwoscomplement(PCM)Adaptive32,44.1,48
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ProductFolderLink(s):PCM2906B
Not Recommended for New Designs