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TA8276HQ2004-05-101TOSHIBABipolarLinearIntegratedCircuitSiliconMonolithicTA8276HQMaxPower35WBTL×4chAudioPowerICTheTA8276HQis4chBTLaudiopoweramplifierforcaraudioapplication.ThisICcangeneratemorehighpower:POUTMAX=35WasitisincludedthepurecomplementaryPNPandNPNtransistoroutputstage.Itisdesignedlowdistortionratiofor4chBTLaudiopoweramplifier,built-instand-byfunction,mutingfunction,outputclippingdetectionanddiagnosiscircuitwhichcandetectoutputtoVCC/GNDshortandovervoltageinputmode.Additionally,theAUXamplifierandvariouskindofprotectorforcaraudiousearebuilt-in.Features•Highpower:POUTMAX(1)=35W(typ.)(VCC=14.4V,f=1kHz,JEITAmax,RL=4Ω):POUTMAX(2)=31W(typ.)(VCC=13.7V,f=1kHz,JEITAmax,RL=4Ω):POUT(1)=23W(typ.)(VCC=14.4V,f=1kHz,THD=10%,RL=4Ω):POUT(2)=20W(typ.)(VCC=13.2V,f=1kHz,THD=10%,RL=4Ω)•Built-inoutputclippingdetectionanddiagnosiscircuit(pin25)•Lowdistortionratio:THD=0.02%(typ.)(VCC=13.2V,f=1kHz,POUT=5W,RL=4Ω)•Lownoise:VNO=0.10mVrms(typ.)1.(VCC=13.2V,Rg=0Ω,GV=26dB,BW=20Hz~20kHz)•Built-instand-byswitch(pin4)•Built-inmutingfunction(pin22)•Built-inAUXamplifierfromsingleinputto2channelsoutput(pin16)•Built-invariousprotectioncircuit:Thermalshutdown,overvoltage,outtoGND,outtoVCC,outtooutshort,speakerburned•Operatingsupplyvoltage:VCC(opr)=9~18VNote1:Installtheproductcorrectly.Otherwise,itmayresultinbreakdown,damageand/ordegradationtotheproductorequipment.Note2:Theseprotectionfunctionsareintendedtoavoidsomeoutputshortcircuitsorotherabnormalconditionstemporarily.TheseprotectfunctionsdonotwarranttopreventtheICfrombeingdamaged.-Incaseoftheproductwouldbeoperatedwithexceededguaranteedoperatingranges,theseprotectionfeaturesmaynotoperateandsomeoutputshortcircuitsmayresultintheICbeingdamaged.Weight:7.7g(typ.)TA8276HQ2004-05-102BlockDiagramNote3:Someofthefunctionalblocks,circuits,orconstantsintheblockdiagrammaybeomittedorsimplifiedforexplanatorypurpose.RLRLRL119875231718192124231215141206RLIN1IN2IN3AUXININ41316C1C1C1C1PRE-GND1025422OUT1(+)PW-GND1OUT1(−)OUT2(+)PW-GND2OUT2(−)OUT3(+)PW-GND3OUT3(−)OUT4(+)PW-GND4OUT4(−)TABVCC1VCC2C3R1C4C2:PRE-GND:PW-GNDSTBYCLIPOUT&DIAGNOSISOUTRIPMUTEC5C6TA8276HQ2004-05-103Figure2Withpin4settoHigh,PoweristurnedONON4OFF10kΩtoBIASCUTTINGCIRCUIT≈2VBEVCCPowerCautionandApplicationMethod(Descriptionismadeonlyonthesinglechannel.)1.VoltageGainAdjustmentThisIChasnoNF(negativefeedback)terminals.Therefore,thevoltagegaincan’tadjusted,butitmakesthedeviceaspaceandtotalcostssaver.ThevoltagegainofAmp.1:GV1=0dBThevoltagegainofAmp.2A,B:GV2=20dBThevoltagegainofBLTConnection:GV(BTL)=6dBTherefore,thetotalvoltagegainisdecidedbyexpressionbelow.GV=GV1+GV2+GV(BTL)=0+20+6=26dB2.Stand-bySWFunction(pin4)Bymeansofcontrollingpin4(stand-byterminal)tohighandlow,thepowersupplycanbesettoONandOFF.Thethresholdvoltageofpin4issetatabout3VBE(typ.),andthepowersupplycurrentisabout2µA(typ.)atthestand-bystate.ControlVoltageofpin4:VSBStand-byPowerVSB(V)ONOFF0~1.5OFFON3~VCCAdjustageofStand-bySW(1)SinceVCCcandirectlybecontrolledtoONorOFFbythemicrocomputer,theswitchingrelaycanbeomitted.(2)Sincethecontrolcurrentismicroscopic,theswitchingrelayofsmallcurrentcapacityissatisfactoryforswitchingAmp.1InputAmp.2AAmp.2BFigure1BlockDiagramTA8276HQ2004-05-1043.MutingFunction(pin22)Bymeansofcontrollingpin22lessthan0.5V,itcanmaketheaudiomutingcondition.ThemutingtimeconstantisdecidedbyR1andC4andthesepartsisrelatedthepopnoiseatpowerON/OFF.Theseriesresistance;R1mustbesetuplessthan10kΩtogetenoughmutingattenuation.Themutingfunctionhavetobecontrolledbyatransistor,FETandµ-COMportwhichhasIMUTE250µAability.Pin22terminalvoltagehasthetemperaturecharacteristicsof4.6V(lowtemperature)to3.2V(hightemperature).Therefore,itisneedtodesignwithattentionasusingthemicrocontrollerofwhichoperatingvoltageislessthan5V.Terminal22maynotbepulledupandshallbecontrolledbyOPEN/LOW.Whenitisobligedtodo,itmustbepulledupviadiode,becauseithastodefendflowingreversecurrenttointernalcircuitofpin22.–ConventionalMethod–VCCLargecurrentcapacityswitchBATTERYVCCFROMMICROCOMPUTERBATTERYRELAYVCCSmallcurrentcapacityswitchBATTERYStand-ByVCCDIRECTLYFROMMICROCOMPUTERBATTERYStand-By–Stand-bySwitchMethod–Figure3Figure5MuteAttenuation−VMUTE(V)PointAvoltage:VMUTE(V)ATT–VMUTEMuteattenuationATT(dB)10kΩ5kΩVCC=13.2VPo=10WPL=4Ωf=1kHzBW=400~30kHz−10000.40.811.21.622.42.83−80−60−40−20020Figure4MutingFunctionR1I(100µA)22IMUTEIMUTE(OFF)AVMUTEC4RecommendedApplicationApplicationforpulledupR1I(100µA)22IMUTEIMUTE(OFF)VMUTEC4TA8276HQ2004-05-1054.AUXInput(pin16)Thepin16isforinputterminalofAUXamplifier.Thetotalgainis0dBbyusingofAUXamplifier.Therefore,theµ-COMcandirectlydrivetheAUXamplifier.BEEPsoundorvoicesynthesizersignalcanbeinputtopin16directly.WhenAUXfunctionisnotused,thispinmustbeconnectedtoPRE-GND(pin13)viaacapacitor.5.DiagnosisOutput(pin25)Thisdiagnosisoutputterminalofpin25hasopencollectoroutputstructureonchipasshowninFigure7.Incasediagnosiscircuitthatdetectunusualcaseisoperated,NPNTr.(Q1)isturnedon.ItispossibletoprotectallthesystemofapparatusaswellaspowerICprotection.Incaseofbeingunusedthisfunction,usethisICasopen-connectiononpin2