Datasheet

DETAILEDDESCRIPTION
ClockandReset
OperationModeSelection
PowerConfigurationSelect/HostDetection
FunctionSelect(PCM2706/7)
PCM2704, ,PCM2705
PCM2706,PCM2707
www.ti.com .......................................................................................................................................................SLES081F–JUNE2003–REVISEDJANUARY2009
ForbothUSBandaudiofunctions,thePCM2704/5/6/7requiresa12-MHz(±500ppm)clock,whichcanbe
generatedbythebuilt-inoscillatorusinga12-MHzcrystalresonator.The12-MHzcrystalresonatormustbe
connectedtoXTI(pin28forPCM2704/5,pin12forPCM2706/7)andXTO(pin1forPCM2704/5,pin13for
PCM2706/7)withonelarge(1-MΩ)resistorandtwosmallcapacitors,thecapacitanceofwhichdependsonthe
specifiedloadcapacitanceofthecrystalresonator.AnexternalclockcanbesuppliedfromXTI(pin28for
PCM2704/5,pin12forPCM2706/7).Ifanexternalclockissupplied,XTO(pin1forPCM2704/5,pin13for
PCM2706/7)mustbeleftopen.Becausenoclockdisablingpinisprovided,itisnotrecommendedtousethe
externalclocksupply.SSPND(pin27forPCM2704/5,pin11forPCM2706/7)isunabletouseclockdisabling.
ThePCM2704/5/6/7hasaninternalpower-onresetcircuit,anditworksautomaticallywhenV
DD
(pin7for
PCM2704/5,pin21forPCM2706/7)exceeds2Vtypical(1.6V–2.4V),whichisequivalenttoV
BUS
(pin10for
PCM2704/5,pin24forPCM2706/7)exceeding3Vtypicalforbus-poweredapplications.Approximately700µsis
requireduntilinternalresetrelease.
ThePCM2704/5/6/7hasthefollowingmode-selectpins.
PSEL(pin4forPCM2704/5,pin16forPCM2706/7)isdedicatedtoselectingthepowersource.Thisselection
affectstheconfigurationdescriptor.Whileinbus-poweredoperation,maximumpowerconsumptionfromV
BUS
is
determinedbyHOST(pin21forPCM2704/5,pin3forPCM2706/7).Forself-poweredoperation,HOSTmustbe
connectedtoV
BUS
oftheUSBbuswithapulldownresistortodetectattachanddetach.(Toavoidexcessive
suspendcurrent,thepulldownshouldbeahigh-valueresistor.)
Table1.PowerConfigurationSelect
PSELDESCRIPTION
0Self-powered
1Bus-powered
HOSTDESCRIPTION
0DetachedfromUSB(self-powered)/100mA(bus-powered)
1AttachedtoUSB(self-powered)/500mA(bus-powered)
FSEL(pin9)determinesthefunctionofFUNC0–FUNC3(pins4,5,18,and19)andDOUT(pin17).WhentheI
2
S
interfaceisrequired,FSELmustbesettoLOW.Otherwise,FSELmustbesettoHIGH.
Table2.FunctionSelect
FSELDOUTFUNC0FUNC1FUNC2FUNC3
0Dataout(I
2
S)LRCK(I
2
S)BCK(I
2
S)SYSCK(I
2
S)Datain(I
2
S)
1S/PDIFdataNexttrack(HID)
(1)
Previoustrack(HID)
(1)
Stop(HID)
(1)
Play/pause(HID)
(1)
(1)ValidonthePCM2706;nofunctionassignedonthePCM2707.
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ProductFolderLink(s):PCM2704PCM2705PCM2706PCM2707
PCM2704 and PCM2705
Not Recommended For New Designs