Tkool Electronics

DescriptionTIP122isanNPNDarlingtontransistor.Darlingtontransistormeanstherearetwotransistorinonepackageconnectedtoincreasegainatoutput.TIP122transistorhasalotofgoodfeatureslike5Acollectorcurrent,maxemitter-basevoltageis5V,maxcollectordissipationis65watt,minimummaximumcurrentgainisequalto1000.Thistransistorisdesignedtouseasaswitchandforamplificationpurposes.CatalogDescriptionTIP122ComponentDatasheetTIP122PinoutTIP122FeaturesTIP122ApplicationsTIP122EnvironmentalandExportClassificationsTIP122ParametersWorkingofTIP122HowtoSafelyLongRuninaCircuitDarlingtonCircuitSchematicWheretouseTIP122HowtouseTIP122TIP122ReplacementandEquivalentComplementofTIP122TIP122AlternativeNPNTransistorsTIP122SameFamilyTransistorsAdditionalResourcesFAQOrdering&QuantityTIP122ComponentDatasheetResourceTypeLinkDatasheetsTIP120-22TIP120-22,TIP125-27TO220B03PkgDrawingPCNObsolescence/EOLMultipleDevices19/Jun/2009MultDeviceEOL19/May/2017PCNDesign/SpecificationHeatsinkDesingChanges24/Feb/2014Logo17/Aug/2017PCNPackagingTapeandBox/ReelBarcodeUpdate07/Aug/2014MultDevices24/Oct/2017HTMLDatasheetTO220B03PkgDrawingTIP122PinoutPinNumberPinNameDescription1BaseItgovernsthebiasingofthetransistorandworkstoturnONorOFFthetransistor.2CollectorCurrentflowsinthroughcollector,usuallyconnectedtoload3EmitterCurrentcomesoutbytheemitter,itisusuallylinkedtoground.TIP122FeaturesHighDCCurrentGainhFE=2500(Typ)@IC=4.0AdcCollectorEmitterSustainingVoltage@100mAdcVCEO(sus)=60Vdc(Min)TIP120,TIP125=80Vdc(Min)TIP121,TIP126=100Vdc(Min)TIP122,TIP127LowCollectorEmitterSaturationVoltageVCE(sat)=2.0Vdc(Max)@IC=3.0Adc=4.0Vdc(Max)@IC=5.0AdcMonolithicConstructionwithBuiltInBaseEmitterShuntResistorsPbFreePackagesareAvailable*TIP122ApplicationsAudioAmplifierAudioAmplifierStagesAudioPreamplifiersSwitchingLoadsUnder5ATIP122EnvironmentalandExportClassificationsAttributeDescriptionRoHSStatusRoHSnon-compliantMoistureSensitivityLevel(MSL)1(Unlimited)TIP122ParametersBaseProductNumberTIP122CategoryDiscreteSemiconductorProducts-Transistors-Bipolar(BJT)-SingleCollector-BaseVoltageVCBO100VConfigurationSingleCurrent-Collector(Ic)(Max)5ACurrent-CollectorCutoff(Max)500ADCCurrentGain(hFE)(Min)@Ic,Vce1000@3A,3VDescriptionTRANSNPNDARL100V5ATO220ABDetailedDescriptionBipolar(BJT)TransistorEmitter-BaseVoltageVEBO5VFactoryPackQuantity200Height9.4mmLength10.67mmManufacturerONSemiconductorManufacturerProductNumberTIP122MaximumCollectorCut-offCurrent200uAMaximumDCCollectorCurrent5AMaximumOperatingTemperature+150CMinimumOperatingTemperature-65CMountingStyleThroughHoleMountingTypeThroughHoleOperatingTemperature-65C~150C(TJ)PackagingBulkPartStatusObsoletePower-Max2WProductTypeDarlingtonTransistorsSeriesTIP122SubcategoryTransistorsTransistorTypeNPN-DarlingtonUnitWeight0.042329ozVceSaturation(Max)@Ib,Ic4V@20mA,5AVoltage-CollectorEmitterBreakdown(Max)100VWidth4.83mmWorkingofTIP122Thistransistorisrecognizedforitshighercurrentgainwhichis1000andhighercollectorcurrent5amperes,therefore,itisusuallyusedtoswitchThistransistorhaslessbaseandemitterVoltageofthemerely5VhenceforthcanbeeffortlesslyorganizedbyaLogicinstrumentsuchasamicrocontrollerThoughprecautionhastobeengagedtocheck,ifthelogicinstrumentscanfontupto120mA.ThoughTIP122hasextraordinarycurrentatcollectorandcurrentgain,itisimpartiallymodesttoswitchtheexpedientmeanwhileithasanEmitter-Basevoltage(VBE)oftheonly5VandIbofmerely120mA.HowtoSafelyLongRuninaCircuitTogetbetterperformancewiththisdarlingtiontransistorwesuggesttoalwaysstayingbelowitsmaximumratings.Donotoperateitincircuitsusingmorethan100V.Donotprovideloadmorethan5A.Alwaysuseasuitablebaseresistortoproviderequiredcurrentatitsbase.Useasuitableheatsinktosaveitfromoverheatinganddostoreoruseitintemperaturebelow-65centigradeandabove+150centigrade.DarlingtonCircuitSchematicWheretouseTIP122Thistransistorisknownforitshighcurrentgain(hfe=1000)andhighcollectorcurrent(IC=5A)henceitisnormallyusedtocontrolloadswithhighcurrentorinapplicationswherehighamplificationisrequired.ThistransistorhasalowBase-EmitterVoltageoftheonly5VhencecanbeeasilycontrolledbyaLogicdevicelikemicrocontrollers.Althoughcarehastobetakentocheckifthelogicdevicecansourceupto120mA.So,ifyoulookingforatransistorthatcouldbeeasilycontrolledbyaLogicdevicetoswitchhighpowerloadsortoamplifyhighcurrentthenthisTransistormightbeanidealchoiceforyourapplication.HowtouseTIP122AlthoughTIPhashighcollectorcurrentandcurrentgain,itisfairlysimpletocontrolthedevicesinceithasanEmitter-Basevoltage(VBE)ofonly5Vandbasecurrentofonly120mA.InthebelowcircuitIhaveusedtheTIP122tocontrola48Vmotorwhichhasacontinuouscurrentofabout3A.Thecontinuescollectorcurrentofthistransistoris5Aandourloadconsumesonly3Awhichisfine.Themaximumbasecurrentisabout120mA,butIhaveusedhighvalueof100ohmresistortolimititto42mA.Youcanuseevena1Kresistorifyourcollectorcurrentrequirementisless.Thepeak(pulse)currentofthistransistoris8Asomakesureyourmotordoesnotconsumemorethanthat.Thisisjustamodelcircuitdiagramthatshowstheworkingonthistransistoritcannotbeusedassuch.So,similarlyyoucancontrolyourloadinthesameway.TIP122ReplacementandEquivalentTIP132,TIP102,NTE261,NTE263,2N6045,2N6045G,2SD2495,BDT65B,2N6532,BDT63B,BDW43,TIP142T(PinconfigurationofsometransistorsmaydifferfromTIP122,checkpinconfigurationbeforereplacinginacircuit)TIP22isadarlingtionpairtransistormanufacturedinTO-220package,itsagoodtransistortouseasahighgainswitchoramplifier.ComplementofTIP122ThecomplementoftheTIP122transistorisTIP127.TIP122AlternativeNPNTransistorsBC547,BC548,BC549,BC636,BC639,2N2369,2N3055,2N3904,2N3906,2SC5200TIP122SameFamilyTransistorsNPNFamilytransistorsareTIP120,TIP121,TIP122,andPNPFamilyareTIP125,TIP126,TIP127(PNP)AdditionalResourcesAttributeDescriptionOtherNamesTIP122FSTIP122FS-NDTIP122FS-NDRTIP122OSFAQWhatisTIP122transistor?TIP122TransistorisanNPNDarlingtontransistor....TIP122Darlingtontransistorhasalotofgoodfeatures,like5Acollectorcurrent,maximumemitter-basevoltageis5V,maximumcollectordissipationis65watt,andsoon.Thistransistorismanufacturedtouseasaswitchandforamplificationpurposes.WhattypeofpackageisusedforTIP122transistor?TheTIP122isasiliconNPNDarlingtontransistorinaTO-220typepackagedesignedforgeneralpurposeamplifierandlow-speedswitchingapplications.HowdoyoutestatransistorTIP122?Harvino.Theproperwaytotestistosetyourdmmtodiodetest(usually2ksettingontheohmscale).Transistorshavethreelegs;anemitter,abase,andacollector.HowdoIknowifmytransistorisblown?Connectthebaseterminalofthetransistortotheterminalmarkedpositive(usuallycolouredred)onthemultimeter.Connecttheterminalmarkednegativeorcommon(usuallycolouredblack)tothecollectorandmeasuretheresistance.Itshouldreadopencircuit(thereshouldbeadeflectionforaPNPtransistor).Whatarethe3terminalsofatransistor?Abipolartransistorhasterminalslabeledbase,collector,andemitter.Asmallcurrentatthebaseterminal(thatis,flowingbetweenthebaseandtheemitter)cancontrolorswitchamuchlargercurrentbetweenthecollectorandemitterterminals.HowtomakeminiaudioamplifieruseTIP122/TIP127transistor?

MBR1560CT-E3/45-VISHAY

DescriptionTIP122isanNPNDarlingtontransistor.Darlingtontransistormeanstherearetwotransistorinonepackageconnectedtoincreasegainatoutput.TIP122transistorhasalotofgoodfeatureslike5Acollectorcurrent,maxemitter-basevoltageis5V,maxcollectordissipationis65watt,minimummaximumcurrentgainisequalto1000.Thistransistorisdesignedtouseasaswitchandforamplificationpurposes.CatalogDescriptionTIP122ComponentDatasheetTIP122PinoutTIP122FeaturesTIP122ApplicationsTIP122EnvironmentalandExportClassificationsTIP122ParametersWorkingofTIP122HowtoSafelyLongRuninaCircuitDarlingtonCircuitSchematicWheretouseTIP122HowtouseTIP122TIP122ReplacementandEquivalentComplementofTIP122TIP122AlternativeNPNTransistorsTIP122SameFamilyTransistorsAdditionalResourcesFAQOrdering&QuantityTIP122ComponentDatasheetResourceTypeLinkDatasheetsTIP120-22TIP120-22,TIP125-27TO220B03PkgDrawingPCNObsolescence/EOLMultipleDevices19/Jun/2009MultDeviceEOL19/May/2017PCNDesign/SpecificationHeatsinkDesingChanges24/Feb/2014Logo17/Aug/2017PCNPackagingTapeandBox/ReelBarcodeUpdate07/Aug/2014MultDevices24/Oct/2017HTMLDatasheetTO220B03PkgDrawingTIP122PinoutPinNumberPinNameDescription1BaseItgovernsthebiasingofthetransistorandworkstoturnONorOFFthetransistor.2CollectorCurrentflowsinthroughcollector,usuallyconnectedtoload3EmitterCurrentcomesoutbytheemitter,itisusuallylinkedtoground.TIP122FeaturesHighDCCurrentGainhFE=2500(Typ)@IC=4.0AdcCollectorEmitterSustainingVoltage@100mAdcVCEO(sus)=60Vdc(Min)TIP120,TIP125=80Vdc(Min)TIP121,TIP126=100Vdc(Min)TIP122,TIP127LowCollectorEmitterSaturationVoltageVCE(sat)=2.0Vdc(Max)@IC=3.0Adc=4.0Vdc(Max)@IC=5.0AdcMonolithicConstructionwithBuiltInBaseEmitterShuntResistorsPbFreePackagesareAvailable*TIP122ApplicationsAudioAmplifierAudioAmplifierStagesAudioPreamplifiersSwitchingLoadsUnder5ATIP122EnvironmentalandExportClassificationsAttributeDescriptionRoHSStatusRoHSnon-compliantMoistureSensitivityLevel(MSL)1(Unlimited)TIP122ParametersBaseProductNumberTIP122CategoryDiscreteSemiconductorProducts-Transistors-Bipolar(BJT)-SingleCollector-BaseVoltageVCBO100VConfigurationSingleCurrent-Collector(Ic)(Max)5ACurrent-CollectorCutoff(Max)500ADCCurrentGain(hFE)(Min)@Ic,Vce1000@3A,3VDescriptionTRANSNPNDARL100V5ATO220ABDetailedDescriptionBipolar(BJT)TransistorEmitter-BaseVoltageVEBO5VFactoryPackQuantity200Height9.4mmLength10.67mmManufacturerONSemiconductorManufacturerProductNumberTIP122MaximumCollectorCut-offCurrent200uAMaximumDCCollectorCurrent5AMaximumOperatingTemperature+150CMinimumOperatingTemperature-65CMountingStyleThroughHoleMountingTypeThroughHoleOperatingTemperature-65C~150C(TJ)PackagingBulkPartStatusObsoletePower-Max2WProductTypeDarlingtonTransistorsSeriesTIP122SubcategoryTransistorsTransistorTypeNPN-DarlingtonUnitWeight0.042329ozVceSaturation(Max)@Ib,Ic4V@20mA,5AVoltage-CollectorEmitterBreakdown(Max)100VWidth4.83mmWorkingofTIP122Thistransistorisrecognizedforitshighercurrentgainwhichis1000andhighercollectorcurrent5amperes,therefore,itisusuallyusedtoswitchThistransistorhaslessbaseandemitterVoltageofthemerely5VhenceforthcanbeeffortlesslyorganizedbyaLogicinstrumentsuchasamicrocontrollerThoughprecautionhastobeengagedtocheck,ifthelogicinstrumentscanfontupto120mA.ThoughTIP122hasextraordinarycurrentatcollectorandcurrentgain,itisimpartiallymodesttoswitchtheexpedientmeanwhileithasanEmitter-Basevoltage(VBE)oftheonly5VandIbofmerely120mA.HowtoSafelyLongRuninaCircuitTogetbetterperformancewiththisdarlingtiontransistorwesuggesttoalwaysstayingbelowitsmaximumratings.Donotoperateitincircuitsusingmorethan100V.Donotprovideloadmorethan5A.Alwaysuseasuitablebaseresistortoproviderequiredcurrentatitsbase.Useasuitableheatsinktosaveitfromoverheatinganddostoreoruseitintemperaturebelow-65centigradeandabove+150centigrade.DarlingtonCircuitSchematicWheretouseTIP122Thistransistorisknownforitshighcurrentgain(hfe=1000)andhighcollectorcurrent(IC=5A)henceitisnormallyusedtocontrolloadswithhighcurrentorinapplicationswherehighamplificationisrequired.ThistransistorhasalowBase-EmitterVoltageoftheonly5VhencecanbeeasilycontrolledbyaLogicdevicelikemicrocontrollers.Althoughcarehastobetakentocheckifthelogicdevicecansourceupto120mA.So,ifyoulookingforatransistorthatcouldbeeasilycontrolledbyaLogicdevicetoswitchhighpowerloadsortoamplifyhighcurrentthenthisTransistormightbeanidealchoiceforyourapplication.HowtouseTIP122AlthoughTIPhashighcollectorcurrentandcurrentgain,itisfairlysimpletocontrolthedevicesinceithasanEmitter-Basevoltage(VBE)ofonly5Vandbasecurrentofonly120mA.InthebelowcircuitIhaveusedtheTIP122tocontrola48Vmotorwhichhasacontinuouscurrentofabout3A.Thecontinuescollectorcurrentofthistransistoris5Aandourloadconsumesonly3Awhichisfine.Themaximumbasecurrentisabout120mA,butIhaveusedhighvalueof100ohmresistortolimititto42mA.Youcanuseevena1Kresistorifyourcollectorcurrentrequirementisless.Thepeak(pulse)currentofthistransistoris8Asomakesureyourmotordoesnotconsumemorethanthat.Thisisjustamodelcircuitdiagramthatshowstheworkingonthistransistoritcannotbeusedassuch.So,similarlyyoucancontrolyourloadinthesameway.TIP122ReplacementandEquivalentTIP132,TIP102,NTE261,NTE263,2N6045,2N6045G,2SD2495,BDT65B,2N6532,BDT63B,BDW43,TIP142T(PinconfigurationofsometransistorsmaydifferfromTIP122,checkpinconfigurationbeforereplacinginacircuit)TIP22isadarlingtionpairtransistormanufacturedinTO-220package,itsagoodtransistortouseasahighgainswitchoramplifier.ComplementofTIP122ThecomplementoftheTIP122transistorisTIP127.TIP122AlternativeNPNTransistorsBC547,BC548,BC549,BC636,BC639,2N2369,2N3055,2N3904,2N3906,2SC5200TIP122SameFamilyTransistorsNPNFamilytransistorsareTIP120,TIP121,TIP122,andPNPFamilyareTIP125,TIP126,TIP127(PNP)AdditionalResourcesAttributeDescriptionOtherNamesTIP122FSTIP122FS-NDTIP122FS-NDRTIP122OSFAQWhatisTIP122transistor?TIP122TransistorisanNPNDarlingtontransistor....TIP122Darlingtontransistorhasalotofgoodfeatures,like5Acollectorcurrent,maximumemitter-basevoltageis5V,maximumcollectordissipationis65watt,andsoon.Thistransistorismanufacturedtouseasaswitchandforamplificationpurposes.WhattypeofpackageisusedforTIP122transistor?TheTIP122isasiliconNPNDarlingtontransistorinaTO-220typepackagedesignedforgeneralpurposeamplifierandlow-speedswitchingapplications.HowdoyoutestatransistorTIP122?Harvino.Theproperwaytotestistosetyourdmmtodiodetest(usually2ksettingontheohmscale).Transistorshavethreelegs;anemitter,abase,andacollector.HowdoIknowifmytransistorisblown?Connectthebaseterminalofthetransistortotheterminalmarkedpositive(usuallycolouredred)onthemultimeter.Connecttheterminalmarkednegativeorcommon(usuallycolouredblack)tothecollectorandmeasuretheresistance.Itshouldreadopencircuit(thereshouldbeadeflectionforaPNPtransistor).Whatarethe3terminalsofatransistor?Abipolartransistorhasterminalslabeledbase,collector,andemitter.Asmallcurrentatthebaseterminal(thatis,flowingbetweenthebaseandtheemitter)cancontrolorswitchamuchlargercurrentbetweenthecollectorandemitterterminals.HowtomakeminiaudioamplifieruseTIP122/TIP127transistor?

IntroductionInordertosolvetheproblemoftransientdistortion,thetypicalapplicationcircuitofLM3886poweramplifierischangedtothecurrentnegativefeedbacktype.Thecurrentsampleflowingthroughthespeakervoicecoilisfedbacktothepoweramplifierinputterminalviaresistance,andtheloudspeakersystemisalsoincludedinthefeedbacksystem.CatalogIntroductionCatalogITypicalpoweramplifiercircuitIIImprovedPowerAmplifierCircuitOrdering&QuantityITypicalpoweramplifiercircuitThepoweramplifiercircuitmadeofLM3886consistsoftwoparts:pre-amplifierandpoweramplifier.ThepreamplifierconsistsofanintegratedoperationalamplifierNE5534,whichprovidesavoltagegainofabout5times.ThepoweramplifieriscomposedofLM3886,whichprovidesavoltagegainofabout10times.Therefore,thefullpoweroutputcanbeachievedbyinputtingabout0.5Vsignalattheinputend.Figure1onlyshowstheLM3886dualpowersupplycircuit,whichcanalsoworkinasinglepowersupply.Consideringfromtheaspectofsoundquality,theaudioamplifiercircuitgenerallydoesnotusesinglepowersupply,butdualpowersupply.Figure1.typicalpoweramplifiercircuitThetypicalapplicationcircuitofLM3886adoptsthetraditionalnegativevoltagefeedbackmode.Negativevoltagefeedbackcanimprovethefrequencycharacteristicsofpoweramplifierandreducenonlineardistortion,butthesoundislackofstrength.Asthevolumeincreases,thelowfrequencywillbecometight,dryandhard,andthedistortionwillincrease.Atthesametime,thehighfrequencybecomessharpandharsh,andthemusicanditsdefinitionaregreatlyreduced.Thisistheso-calledTransientIntermodulationDistortion.Thetransientintermodulationdistortionismainlycausedbytheintroductionofdeepnegativefeedback.Voltagetypenegativefeedbackiseffectivetoimprovethenonlineardistortionofpoweramplifier,butitcannottakeintoaccountthetransientdistortionatthesametime.IIImprovedPowerAmplifierCircuitTheimprovedcircuitisshowninFigure2.Thelow-frequencyspectralgainofpoweramplifierisdeterminedbytheratioofR3andR4.C3andR5determinethehigh-frequencygainofpoweramplifier.DuetothelargecapacitancereactanceofC3atlowfrequency,thecurrentfeedbackisterminatedatlowfrequency,whilethehighfrequencyisimprovedbycurrentnegativefeedback.Theresultisthatthetotalbandwidthisimprovedandthetransientdistortionisgreatlyreduced.Theselectionoffeedbackcomponentsshouldbebasedontheimpedanceandinductanceoftheloudspeaker,sothatthelow-frequencygainis2-3timesofthehigh-frequencygain.Formerpoweramplifiersoftendesignedthefrequencycharacteristicstobeflat,whichdidnotachievegoodsoundeffects.Inordertoimprovethesoundeffectofthepoweramplifier,weshouldusethenegativefeedbackcircuittoconsciouslyincreasethelowfrequencygaintoachievethebesteffect,whichalsomeetstherequirementsofthelargedynamicsoundeffectoftodayshometheater.Figure2.schematicdiagramofpoweramplifiercircuitThesoundeffectofthismachineisexcellent.Thelowfrequencyextensionisincreasedanditisflexible.Thehighfrequencyisclearandsmooth.Theresolutionisgreatlyimproved,andthemetallicsoundiscompletelydisappeared.Evenifthevolumewasdoubled,nosignificantdistortionwasheard.DescriptionLM3886isahigh-performanceaudiopoweramplifier.Undertheratedworkingvoltage,itiscapableofdelivering68Wofcontinuousaveragepowertoa4loadand38Winto8with0.1%THD+Nfrom20Hz20kHz.TheperformanceoftheLM3886,utilizingitsSelfPeakInstantaneousTemperature(Ke)(SPiKe)protectioncircuitry,putsitinaclassabovediscreteandhybridamplifiersbyprovidinganinherently,dynamicallyprotectedSafeOperatingArea(SOA).SPiKeprotectionmeansthatthesepartsarecompletelysafeguardedattheoutputagainstovervoltage,undervoltage,overloads,includingshortstothesupplies,thermalrunaway,andinstantaneoustemperaturepeaks.TheLM3886maintainsanexcellentsignal-to-noiseratioofgreaterthan92dBwithatypicallownoisefloorof2.0V.ItexhibitsextremelylowTHD+Nvaluesof0.03%attheratedoutputintotheratedloadovertheaudiospectrum,andprovidesexcellentlinearitywithanIMD(SMPTE)typicalratingof0.004%.CatalogDescriptionCADModelsFeaturesApplicationsParametersElectricalCharacteristicsPinoutCircuitDiagramPackageProductComplianceComponentDatasheetProductManufacturerOrdering&QuantityCADModelsLM3886SymbolLM3886FootprintFeatures68WCont.Avg.OutputPowerinto4atVCC=28V38WCont.Avg.OutputPowerinto8atVCC=28V50WCont.Avg.OutputPowerinto8atVCC=35V135WInstantaneousPeakOutputPowerCapabilitySignal-to-NoiseRatio92dBAnInputMuteFunctionOutputProtectionfromaShorttoGroundortotheSuppliesviaInternalCurrentLimitingCircuitryOutputOver-VoltageProtectionagainstTransientsfromInductiveLoadsSupplyUnder-VoltageProtection,notAllowingInternalBiasingtoOccurwhen|VEE|+|VCC|12V,thusEliminatingTurn-OnandTurn-OffTransients11-LeadTO-220PackageWideSupplyRange20V-94VApplicationsComponentstereoCompactstereoSelf-poweredspeakersSurround-soundamplifiersHifg-endstereoTVsParametersAudioinputtypeAnalogInputArchitectureClass-ABSpeakerchannels(Max)MonoPowerstagesupply(Max)(V)94Powerstagesupply(Min)(V)20Load(Min)(ohms)4Outputpower(W)68SNR(dB)110THD+N@1kHz(%)0.03Iq(Typ)(mA)50ControlinterfaceHardwareClosed/openloopOpenAnalogsupply(Min)(V)20Analogsupply(Max)(V)84Powertoparallelbridgetiedload(Max)(W)68PSRR(dB)120Operatingtemperaturerange(C)0to70NumberofTerminals11NumberofFunctions1BrandNameTexasInstrumentsElectricalCharacteristicsThefollowingspecificationsapplyforV+=+28V,V-=-28V,lMUTE=-o.5mAwithRL=4unlessotherwisespecified.LimitsapplyforTA=25℃.PinoutPin1isthepositivepowersupplyV+terminal;Pin2isanemptypin(NC);Pin3istheoutputterminalaftersignalamplification;Pin4isthenegativepowerV-terminal;Pin5isanemptypin(NC)(internallyindependent,butinthe150WLM3886,thispinshouldbeconnectedtoV+);Pin6isanemptypin(NC);Pin7istheground(GND)terminal;Pin8isthemuteend.Ifitisnotneeded,itshouldbeconnectedtothev-terminal.Pin9istheinvertinginputofthesignal;Pin10isthenon-invertinginputterminalofthesignal;Pin11isanemptypin(NC)CircuitDiagramPackageLM3886hastwopackagingmethods.Oneisthatthebackplateisnotinsulatedfromtheinnerelectrode,anditmustbeinsulatedwhenaheatsinkisadded.Theotheristhatthebackplateisinsulatedfromtheinternalelectrodes,sothereisnoneedtoconsiderinsulationwhenaddingaheatsink.ProductComplianceECCNEAR99USHTS8542330001ComponentDatasheetDatasheetLM3886DatasheetProductManufacturerTexasInstrumentsInc.(TI)isanAmericantechnologycompanythatdesignsandmanufacturessemiconductorsandvariousintegratedcircuits,whichitsellstoelectronicsdesignersandmanufacturersglobally.ItsheadquartersareinDallas,Texas,UnitedStates.TIisoneofthetoptensemiconductorcompaniesworldwide,basedonsalesvolume.TexasInstrumentssfocusisondevelopinganalogchipsandembeddedprocessors,whichaccountsformorethan80%oftheirrevenue.TIalsoproducesTIdigitallightprocessing(DLP)technologyandeducationtechnologyproductsincludingcalculators,microcontrollersandmulti-coreprocessors.Todate,TIhasmorethan43,000patentsworldwide.

MBR1560CT-E3/45-VISHAY

IIntroductionLM1875isapoweramplifierintegratedblock.Ithasfewperipheralcircuits,largedistortion-freepower,andcanworkwithbothsingleanddualpowersupplies.Italsohasasafeworkingareaprotection(inductiveload)foroverload,overheatingandreversepotentialsuppressioninthecircuit,suitableforhigh-gradeaudiocircuits.AndLM1875isalsosuitableforaudioamplification,servoamplification,bridgeamplification,andpoweramplificationintestsystems.ThisVedioTakeLM1875asanExampletoExplaintheBridgedAudioAmplifierCatalogIIntroductionIIDCNegativeFeedbackBTLPowerAmplifierCircuitIII20WSingle-powerAmplifierCircuitIVLM1875PowerAmplifierCircuitwithHighandLowAdjustmentVCurrentFeedbackPowerAmplifierCircuitOrdering&QuantityIIDCNegativeFeedbackBTLPowerAmplifierCircuitTheLM1875amplifiercircuitissimple,wherethesoundisbeautiful,andhasthetimbreoftheamplifier.Thepoweramplifierproducedbyitcanoutputpowerupto25Wunderpositiveandnegative25Vvoltage.Inordertooutputmorepower,itcanbeconnectedtoBTLcircuit.Theoutputpowerofthefollowingcircuitexceeds60W(8ohmspeaker),whichisdesignedasacurrentnegativefeedbackcircuit,andthesoundismorebeautiful.Inaddition,themainrecommendationofthisboardistocancelC11andC21inFigure1,andaddacapacitorattheinput(changeC11here).ChangethecircuittoaDCamplifier,thesoundeffectwillbebetter.Figure1.LM1875CuircuitIII20WSingle-powerAmplifierCircuitThecircuitisshowninFigure3.ThebasicworkingprincipleoftheLM1875singlepowersupplyandthedualpowersupplyisthesame.Thedifferenceisthatwhenthesinglepowersupplyisused,R1andR2areusedforvoltagedivision,while1/2VCCistakenasthebiasvoltageandaddedtoR3topin1,makingtheoutputvoltagechangeupanddownbasedon1/2VCC.Therefore,themaximumdynamicrangecanbeobtained.Figure2.LM1875CuircuitIVLM1875PowerAmplifierCircuitwithHighandLowAdjustmentFigure3.LM1875CuircuitThecircuitaboveiscomposedofthreeparts:AnattenuatedtonecontrolcircuitcontrolledbyhighandlowsoundsAnLM1875amplifiercircuitApowersupplycircuit.Thetonepartusesattenuatingtonecircuitscontrolledbyhighandlowbassrespectively,amongwhichR02,R03,C02,C01,W02formabasscontrolcircuit;C03,C04,W03formatreblecontrolcircuit;R04istheisolationresistance,W01isthevolumecontroller,adjustingthevolumeoftheamplifier;C05istheDCblockingcapacitor,topreventtheLM1875DCpotentialofthesubsequentstagefromaffectingthetonecircuitoftheprecedingstage.TheamplifyingcircuitadoptsLM1875,R08,R09,C06.Amongthem,themagnificationofthecircuitisdeterminedbytheratioofR08andR09;andC06isusedtostabilizetheDCzeropotentialdriftofthe4thpinofLM1875,butithasacertainimpactonthesoundquality;C07,R10istopreventtheamplifierfromgeneratinglow-frequencyself-excitation.Theloadimpedanceofthisamplifieris416.Figure4.LM1875CuircuitAsforthepowersupply,inordertoensurethesoundquality,theoutputpowerofthepowertransformershouldnotbelessthan80W,andtheoutputvoltageis2*25V.Thefiltercapacitorusestwo2200F/25Velectrolyticcapacitorsinparallel,andthepositiveandnegativepowersuppliessharefour2200F/25Vcapacitors.Thetwo104monolithiccapacitorsarehigh-frequencyfiltercapacitors,whicharebeneficialtothesoundqualityoftheamplifier.VCurrentFeedbackPowerAmplifierCircuitThecurrentmodepoweramplifierhasbettersoundquality.ThecurrentmodepoweramplifiercircuitusingthepoweramplifierintegratedcircuitLM1875isshowninFigure5.Inthefigure,theresistorR3connectedinserieswiththespeakerRLhasaverysmallvalue.ThecurrentflowingthroughthespeakerflowsthroughR3,andthesamplingfeedbackvoltagegeneratedatbothendsisproportionaltotheoutputcurrent.ThevoltageformedonR3issenttothefeedbackinputoftheamplifierthroughR2toformacurrentnegativefeedback,whichincreasestheoutputimpedanceoftheamplifierandreducesthedampingcoefficient.Theso-calledRubernetworkwascancelledinthecircuit,andonlyC4wasusedastheleadcompensation.AlthoughthesettingofR2preventstheoutputfeedbackcurrentfrombeingfedback100%tothenegativeinputterminal,itpreventstheharmfuleffectsoflargefeedbackontheinputterminal;Atthesametime,thebiasofthepositiveandnegativeinputterminalsisbalanced,andtheDCoffsetoftheoutputterminaliseliminated.Figure5.LM1875CuircuitFirstsoldertwosmall0.22uFcapacitorstothepin③and⑤,andweldtheotherendsofthemtogetherasthegroundterminal.Regardingtheresistancetogrounding,allarebentandweldedatthispoint.The24Vpowercordandoutputcordaredirectlysolderedtotherelevantpins.Short-circuittheinputterminaltoground,soldera10resistortotheRLspeaker,andtestthevoltageoftheoutputterminaltogroundafterpower-on.Ifitislessthan100mVandthereisbasicallynodeviationafterhalfanhour,youcandisconnecttheinputshortcircuitandconnectthespeaker.Afterreadingtheblog,haveyoubetterunderstandLM1875?IfyouarealsointerestedindetailedintroductiontoLM1875,youmaywishtobrowserighthererightnow!Finally,ifyouhaveanyquestionsaboutLM1875,pleasedonothesitatetoleaveamessageinthecommentsectionbelow!IntroductionTheLM393comparatorcanberegardedasequivalenttothemostpopularversionoftheLM358operationalamplifier.Althoughanyoperationalamplifiercanbeusedasavoltagecomparator,theLM393comparatorprovesitsadvantagebyprovidinganopencollectoroutputtomakeitsuitablefordrivingloads.Theoutputtransistorcandriveloadsupto50Vand50mAandissuitablefordrivingmostTTL,MOSandRTLloads.Thetransistorcanalsoisolatetheloadfromthesystemground.ThisVedioIntroducesLM393DualComparatorwithOpenCollectorOutputfromIntegratedCircuitCatalogIntroductionCADCAESymbolsDocumentandMediaECCNUNSPSCLM393PinConfigurationandFunctionsPopularitybyRegionBasicParametersProductManufacturerFeaturesProductRangeAdvantagesAlternativeModelsFunctionalBlockDiagramOrdering&QuantityDocumentandMediaComponentDatasheetLM393DatasheetApplicationNotesApplicationDesignGuidelinesforLM393LM393PinConfigurationandFunctionsTheLM393datasheetprovidedaboveisforyourreference,sothatyoucanunderstandthephysicaldimensionsofallpackagesinmoredetail.Theconfigurationofall8pinsandthefunctionofeachpinareasfollows:ThefunctionofLM393pinsareasfollows:BasicParametersNumberofchannels2OutputtypeOpen-collectorPropagationdelaytime1.3sVs(Max)36VVs(Min)2VVos(offsetvoltage@25C)(Max)5mVIqperchannel(Typ)0.225mAInputbiascurrent(+/-)(Max)50nARail-to-railOutRatingCatalogOperatingtemperaturerange0℃to70℃FeaturesStandardcomparatorVICR(Max)34.5VVICR(Min)0VApprox.price1ku|0.06US$FeaturesImprovedspecificationsofB-versionMaximumrating:upto38VESDrating(HBM):2kVLowinputoffset:0.37mVLowinputbiascurrent:3.5nALowsupply-current:200ApercomparatorFasterresponsetimeof1secExtendedtemperaturerangeforLM393BAvailableintiny2x2mmWSONpackageB-versionisdrop-inreplacementforLM293,LM393andLM2903,AandVversionsCommon-modeinputvoltagerangeincludesgroundDifferentialinputvoltagerangeequaltomaximumratedsupplyvoltage:38VLowoutputsaturationvoltageOutputcompatiblewithTTL,MOS,andCMOSAdvantagesVacuumrobotSinglephaseUPSServerPSUCordlesspowertoolWirelessInfrastructureApplicancesBuildingAutomationFactoryautomationcontrolMotordrivesInfotainmentclusterFunctionalBlockDiagramCADCAESymbolsPackagePinsDownloadPDIP(P)8ViewoptionsSO(PS)8ViewoptionsSOIC(D)8ViewoptionsTSSOP(PW)8ViewoptionsVSSOP(DGK)8ViewoptionsECCNUNSPSCDescriptionValueECCNCodeEAR99HTSCode8542.39.00.01PopularitybyRegionProductManufacturerTexasInstrumentsInc.(TI)isanAmericantechnologycompanythatdesignsandmanufacturessemiconductorsandvariousintegratedcircuits,whichitsellstoelectronicsdesignersandmanufacturersglobally.ItsheadquartersareinDallas,Texas,UnitedStates.TIisoneofthetoptensemiconductorcompaniesworldwide,basedonsalesvolume.TexasInstrumentssfocusisondevelopinganalogchipsandembeddedprocessors,whichaccountsformorethan80%oftheirrevenue.TIalsoproducesTIdigitallightprocessing(DLP)technologyandeducationtechnologyproductsincludingcalculators,microcontrollersandmulti-coreprocessors.Todate,TIhasmorethan43,000patentsworldwide.ProductRangeDevicesBoardsDeveloperToolsARMPROCESSORSAUTOMOTIVEPRODUCTSIDENTIFICATIONSECURITYKinetisCortex-MMicrocontrollersIn-VehicleNetworkNFCLPCCortex-MMicrocontrollersMicrocontrollersandProcessorsRFIDAlternativeModelsLM741LM358LM339LM324Afterreadingtheblog,haveyoubetterunderstandLM393?IfyouarealsointerestedinhowtoDIYyoursolartrackingcarbyusingLM393,youmaywishtobrowserighthererightnow!Finally,ifyouhaveanyquestionsaboutLM393,pleasedonothesitatetoleaveamessageinthecommentsectionbelow!IIntroductionTheLM393isadualvoltagecomparator.thismeansthatitaccepts2inputsforcomparison.TheoutputloadresistanceofLM393comparatorcanbeconnectedtoanypowersupplyvoltagewithintheallowablepowersupplyvoltagerange,andisnotlimitedbythevoltagevalueoftheVccterminal.ThisoutputcanbeusedasasimpleopencircuittogroundSPS(whentheloadresistorisnotused),thesinkcurrentoftheoutputpartislimitedbythevalueofthedriverandthedevicethatcanbeobtained.Whenthelimitcurrent(16mA)isreached,theoutputtransistorwillexitandtheoutputvoltagewillrisequickly.Inthisblog,wewilldiscuss3waystousetheLM393comparatortobuildcircuits,including:InfraredObstacleAvoidanceModule,Ni-CdBatteryCharger,andPWMModulationCircuit.LM393imagesareforreferenceonly.Figure1.LM393ComparatorCatalogIIntroductionIILM393BasedInfraredObstacleAvoidanceModule2.1ModuleDescription2.2DescriptionofModuleParameters2.3ModuleInterfaceDescriptionIIILM393Ni-CdBatteryChargerIVLM393PWMModulationCircuitOrdering&QuantityIILM393BasedInfraredObstacleAvoidanceModuleFigure2.LM393InfraredObstacleAvoidanceModule2.1ModuleDescriptionThesensormodulehasstrongadaptabilitytoambientlight.Ithasapairofinfraredemittingandreceivingtubes.Thetransmittingtubeemitsinfraredraysofafrequency.Whenitencountersanobstacle(reflectingsurface)inthedetectiondirection,itwillbereflectedbackandreceivedbythereceivingtube.Afterthereceivedinfraredlightisprocessedbythecomparatorcircuit,thegreenindicatorlightwilllightup,andthesignaloutputinterfaceoutputsadigitalsignal(alow-levelsignal).Thedetectiondistancecanbeadjustedbythepotentiometerknob.Theeffectivedistancerangeis2-30cm,andtheoperatingvoltageItis3.3V-5V.Thedetectiondistanceofthesensorcanbeadjustedbyapotentiometer,whichhasthecharacteristicsofsmallinterference,easyassemblyandconvenientuse.Itcanbewidelyusedinmanysituationssuchasrobotobstacleavoidance,obstacleavoidancetrolley,pipelinecountingandblackandwhitelinetracking.2.2DescriptionofModuleParametersWhenthemoduledetectsanobstaclesignalinfront,thegreenindicatoronthecircuitboardlightsup,andtheOUTportcontinuouslyoutputsalow-levelsignal.Thedetectiondistanceofthismoduleis2~30cm,andthedetectionangleis35.Inaddition,thedetectiondistancecanbeadjustedbythepotentiometer:Byadjustingthepotentiometerclockwise,thedetectiondistanceincreases;Byadjustingthepotentiometercounterclockwise,thedetectiondistancedecreases;Thesensorisactiveinfraredreflectiondetection,sothereflectivityandshapeofthetargetisthekeytothedetectiondistance.Amongthem,theblackdetectiondistanceissmallandthewhiteislarge;thedistanceofsmallareasissmall,andthedistanceoflargeareasislarge;TheoutputportOUTofthesensormodulecanbedirectlyconnectedtotheIOportofthesingle-chipmicrocomputer,oritcandirectlydrivea5Vrelay;connectionmode:VCC-VCC;GND-GND;OUT-IO;TheLM393comparatorhasthecharacteristicsofstableoperation;3-5VDCpowersupplycanbeusedtopowerthemodule.Whenthepoweristurnedon,theredpowerindicatorlights;has3mmscrewholesforeasyfixingandinstallation;Circuitboardsize:3.2CM*1.4CM;Themodulehasadjustedthethresholdcomparisonvoltagethroughthepotentiometer.Unlessunderspecialcircumstances,pleasedonotadjustthepotentiometeratwill.2.3ModuleInterfaceDescriptionVCCexternal3.3V-5Vvoltage(canbedirectlyconnectedto5vmicrocontrollerand3.3vmicrocontroller);ConnectGNDexternallytoGND;OUTsmallboarddigitaloutputinterface(0and1);Theworkingcurrentiswithin10ma;BarriersensormoduleasshowninFigure3.Figure3.InfraredReflectiveSensorModuleIIILM393Ni-CdBatteryChargerThecost-effectivenickel-cadmiumbatterychargerformedbyLM393comparatorisshowninFigure4,whichhasthefollowingcharacteristics:Figure4.Nickel-CadmiumBatteryChargerConstantcurrentchargingisinterspersedwithlargecurrentdischarge.Theconstantcurrentchargingcurrentisabout300mA,andthedischargecurrentincreasesasthebatteryvoltageincreases.Whenthebatteryisnearlyfull,thedischargecurrentreaches400mA.Chargefor1.5secondsanddischargefor0.5secondsatintervals.Afterthehighcurrentchargingiscompleted,thereisabout5mAtricklecharging.Thebatteryvoltageisdetectedduringdischarge.Becausethevoltageduringchargingisalwayshigherthanthevoltageduringdischarging.Ifthereisanerrorbetweenthedetectionandtheactualworkingstateofthebatteryduringcharging,thedetectioncanmorereflectthecapacityofthebatterywhendischarging.Thenumberofrechargeablebatteriescanbe1to4.For500mAhnickel-cadmiumbatteries,thechargingtimeisabout2hours,whichcanmeetthegeneralneeds.IVLM393PWMModulationCircuitWeknowthatPWMgenerallyrequiresasawtoothwaveandacontrolvoltagetobecomparedwithacomparatortoobtainaPWMpulse.Thecomparator2ofLM393votagecomparatorwillbeusedasaPWMcomparator,whosenon-invertinginputendisthecontrolvoltageinputend,andtheinvertinginputendisthesawtoothwaveinputend.Theoutputterminal(pin7)isusedastheoutputterminaltosendthePWMdimmingsignaltotheIRNpinoftheIRS2540/1viatheisolationdiodeVD.TheLM393circuitofPWMModulationisshowninFigure5below.Figure5.PWMModulationCircuitThegenerationofthesawtoothwaveisrealizedbythecomparator1ofLM393.IfyoudonotlookatthecapacitorC1,thecomparator1isamultivibratorwithasquarewaveoutput.Inordertoobtainthesawtoothwave,acapacitorC1isconnectedinparallelwiththeCOMendoftheoutputendofthecomparator1.ThisisactuallythechargingprocessoftheoutputterminalsR1andC1ofthecomparator1.Ifthecapacitanceofthiscapacitorislargeenough,butbecausethechargingofC1requiresR1,andthedischargeofC1istheoutputtransistorofthecomparator,thentheriseandfallofthevoltageattheoutputofthecomparatorwillbeasymmetric,whichwillformanoscillatingsawtoothwave.Figure6.OscillatingSawtoothWaveDuetotheVBUSapplicationofthepowersupplyofthecircuitinthefigure,itneedstobesteppeddownwithRS,andthevoltageregulationofVD2andthepowersupplybypasscapacitorsC3andC4arerequired.Afterreadingtheblog,haveyoubetterunderstandLM393?IfyouarealsointerestedinhowtoDIYyoursolartrackingcarbyusingLM393,youmaywishtobrowserighthererightnow!Finally,ifyouhaveanyquestionsaboutLM393,pleasedonothesitatetoleaveamessageinthecommentsectionbelow!

MBR1560CT-E3/45-VISHAY

IntroductionLM567isahigh-stabilitylow-frequencyintegratedphase-lockedloopdecoder.Duetoitsgoodnoisesuppressionabilityandcenterfrequencystability,itiswidelyusedinthedecodingofvariouscommunicationequipmentandthedemodulationcircuitofAMandFMsignals.LM567Imagesareforreferenceonly.LM567ToneDecoderCatalogIntroductionDocumentsandMediaPinConfigurationandFunctionsBasicParametersFeaturesApplicationsFunctionalBlockDiagramCircuitDiagramECCNUNSPSCProductManufacturerProductRangeOrdering&QuantityDocumentsandMediaComponentDatasheetsLM567(C)PinConfigurationandFunctionsThedatasheetprovidedaboveisforyourreference,sothatyoucanunderstandthephysicaldimensionsofallpackagesinmoredetail.Theconfigurationofall8pinsandthefunctionofeachpinareasfollows:PinConfigurationAndthefunctionofall8pinsandthefunctionofeachpinareasfollows:PinFunctionBasicParametersBrandNameTexasInstrumentsECCNCodeEAR99FactoryLeadTime1WeekHTSCode8542.39.00.01JESD-30CodeR-PDSO-G8JESD-609Codee3Length4.9mmManufacturerTexasInstrumentsManufacturerPartNumberLM567CMX/NOPBMoistureSensitivityLevel1NumberofFunctions1NumberofTerminals8OperatingTemperature-Max70CPackageBodyMaterialPLASTIC/EPOXYPackageCodeSOPPackageDescriptionSOP-8PackageEquivalenceCodeSOP8,.23PackageShapeRECTANGULARPackageStyleSMALLOUTLINEPartLifeCycleCodeActivePartPackageCodeSOICPbfreeCodeYesPeakReflowTemperature260℃PinCount8QualificationStatusNotQualifiedReachComplianceCodeCompliantRiskRank0.62RohsCodeYesSeatedHeight-Max1.75mmSupplyCurrent-Max15mASupplyVoltage-Nom5VSurfaceMountYESTelecomICTypeTONEDECODERCIRCUITTemperatureGradeCOMMERCIALTerminalFinishMatteTin(Sn)TerminalFormGULLWINGTerminalPitch1.27mmTerminalPositionDUALTime@PeakReflowTemperature-Max(s)NOTSPECIFIEDWidth3.91mmFeatures20to1FrequencyRangeWithanExternalResistorLogicCompatibleOutputWith100-mACurrentSinkingCapabilityBandwidthAdjustableFrom0to14%HighRejectionofOutofBandSignalsandNoiseImmunitytoFalseSignalsHighlyStableCenterFrequencyCenterFrequencyAdjustablefrom0.01Hzto500kHzApplicationsTheLM567tonedecoderisadevicecapableofdetectingwhetheraninputsignaliswithinaselectabledetectionrange.Thedevicehasanopencollectortransistoroutput,soanexternalresistorisrequiredtoreachtheappropriatelogiclevels.Whentheinputsignalisinthedetectionband,thedeviceoutputchangestotheLOWstate.TheinternalfreeoperatingfrequencyoftheVCOdefinesthecenterfrequencyofthedetectionband.AnexternalRCfilterisrequiredtoadjustthisfrequency.Thebandwidthinwhichthedevicewilldetectthedesiredfrequencydependsonthecapacityoftheloopfilterterminal.Usuallya1Fcapacitorisconnectedtothispin.LM567isgenerallyusedinthefollowingsituations:TouchToneDecodingPrecisionOscillatorFrequencyMonitoringandControlWideBandFSKDemodulationUltrasonicControlsCarrierCurrentRemoteControlsCommunicationsPagingDecodersFunctionalBlockDiagramCircuitDiagramThefollowingdescribestheclassiccircuitdiagramofthephase-lockedloopLM567usedincarriercommunicationapplications.Therearemanyapplicationsforit,butthethreecircuitsdescribedbelowhaveallbeentestedbypracticeforreferencebythosewholovecarriercommunication.ClassicCircuitDiagram(1)ClassicCircuitDiagram(2)ClassicCircuitDiagram(3)ECCNUNSPSCDescriptionValueECCNCodeEAR99HTSCode8542.39.00.01ProductManufacturerTexasInstrumentsInc.(TI)isanAmericantechnologycompanythatdesignsandmanufacturessemiconductorsandvariousintegratedcircuits,whichitsellstoelectronicsdesignersandmanufacturersglobally.ItsheadquartersareinDallas,Texas,UnitedStates.TIisoneofthetoptensemiconductorcompaniesworldwide,basedonsalesvolume.TexasInstrumentssfocusisondevelopinganalogchipsandembeddedprocessors,whichaccountsformorethan80%oftheirrevenue.TIalsoproducesTIdigitallightprocessing(DLP)technologyandeducationtechnologyproductsincludingcalculators,microcontrollersandmulti-coreprocessors.Todate,TIhasmorethan43,000patentsworldwide.ProductRangeDevicesBoardsDeveloperToolsARMPROCESSORSAUTOMOTIVEPRODUCTSIDENTIFICATIONSECURITYKinetisCortex-MMicrocontrollersIn-VehicleNetworkNFCLPCCortex-MMicrocontrollersMicrocontrollersandProcessorsRFIDAfterreadingtheblog,haveyoubetterunderstandLM567?IfyouarealsointerestedinhowtouseLM567totestthespeedofyourmotorcycle,youmaywishtobrowserighthererightnow!Finally,ifyouhaveanyquestionsaboutLM567,pleasedonothesitatetoleaveamessageinthecommentsectionbelow!IIntroductionLM567isatonedecodingphase-lockedloopintegratedcircuit.Itiscompactindesign,simpleincircuit,andhasawiderangeofapplications.However,ifusingimproperly,itwillbringtroublesindebugging.ThisblogintroducestheworkingprincipleandtipsabouthowtouseLM567tonedecoderforreadersreference.Figure1.LM567ToneDecoderCatalogIIntroductionIILM567InternalStructurePinFunctionIIILM567WorkingPrincipleApplicationIVTipsofUsingToneDecoderLM567Ordering&QuantityIILM567InternalStructurePinFunctionThenameofLM567isphase-lockedlooptonedecoder,itspackageformuses8-pindualin-line,itsinternalstructureandpinfunctionsareillustratedinFigure2.Itsinternalcircuitstructureiscomposedofquadraturephase,detector,phase-lockedloop,amplifier,etc.TheoperatingvoltagerangeofLM567is4.75-9V,theoperatingfrequencycanreach500KHz,andthestaticoperatingcurrentisonly8mA.Thepin③isthesignalinputterminal,whichrequirestheinputsignaltobegreaterthan25mV.Thepin⑧isthelogicoutputterminal.Itcanbeseenfromthefigurethatitisanopencollectortransistoroutput,whichallowsamaximumsinkcurrentof100mA.Theexternalresistanceandcapacitanceofpins⑤and⑥determinethecenterfrequencyf01/1.1RCofICinternalvoltagecontrolledoscillator.Pins①and②areusuallyconnectedtothegroundseparatelytoformanoutputfilternetworkandalooplow-passfilternetwork.Thecapacitorconnectedtopin②determinesthecapturebandwidth.Thelargerthevalueofthecapacitor,thenarrowertheloopbandwidthis.Figure2.TopViewofLM567IIILM567WorkingPrincipleApplicationWhenthetonedecoderLM567works,itsphase-lockedloopinternalcurrent-controlledoscillatorgeneratesanoscillationsignalofacertainfrequencyandphase.Thissignalissenttothequadraturephasedetectortogetherwiththesignalinputatpin③forcomparison.Whenthefrequencyofthesignalfallswithinagivenpassband,thephase-lockedlooplocksthissignal,andatthesametimetheinternaltransistoroftheLM567iscontrolledtobepoweredup,andtheoutputterminaloftheLM567outputslowlevel.The⑤pinofLM567outputstherectangularsignaloftheinternaloscillator,andthe⑥pinoutputsthesawtoothpulse.Thefrequencyofbothisthesameasthecenterfrequencyoftheinternaloscillator.The②pinistheoutputofthephase-lockedloopphasedetector.ThevoltageonisthesignalafterF/Vconversion.Ifthetonesignalisinputtothe②pin,thenthe⑤pinoutputstheFMsquarewavesignalmodulatedbythe②pininputsignal.FromthebasicfunctionofLM567,LM567canbeusedasanoscillator,modulatorordemodulator.Therefore,itcanbeusedasabasicdeviceinthecircuit.TheapplicationofLM567hasthefunctionofdecodingaspecificfrequencyintheinputsignal,anditiswidelyusedincommunication,remotecontrol,measurement,frequencymonitoring,etc.Figure3.LM567ToneDecoderIVTipsofUsingToneDecoderLM567AlthoughLM567hasaverywiderangeofapplications,ifitisnothandledproperlyduringdesignandapplication,itstillfailstoachievetheexpectedresults,andevenbringstroubletothedebuggingoraffectsthereliabilityoftheproduct.Therefore,itshouldbeconsideredfromthefollowingaspectswhenusingit:1.SetOperatingFrequencyandBandwidthofLM567AccuratelyandAppropriatelyWeknowthattheinternaloscillationfrequencyf0ofLM567canbepre-setwithintherangeof0.1KHzto500KHz,anditscorrespondingbandwidthcanalsobedeterminedasrequiredwithinthefieldrangeof7%f0to14%f0.Therefore,afterthedetectedsignalisdetermined,theinternaloscillationfrequencyf0ofLM567shouldbesettocoincidewiththecenterfrequencyofthemeasuredsignal,andthetimingcomponentsRandCconnectedwiththe5and6feetofLM567shouldbeusedwithhighprecision.Amongthem,thesettingofthecenterfrequencycanbedeterminedbytheresistancevalueofthetunerR.Whenadjusting,itisnecessarytopreventRshortcircuitoropencircuit,otherwisetheoutputlevelof⑧pinwillbelowlevelwhetherthereisinputsignalornot.Theexternalcapacitanceofthe②pinofLM567determinesthecapturebandwidth.Thesmallerthecapacity,thewiderthecapturebandwidth.However,thecapacitancecannotbereducedblindlytoincreasethebandwidth,soasnottoreducetheanti-interferenceabilityoreventriggerfalsely,whichaffectsthereliabilityoftheproduct.2.MaketheCenterFrequencyofthePassbandCoincidewiththeCenterFrequencyoftheOscillationAsMuchAsPossibleItshouldbenotedthatthecenterfrequencyofthepassbanddoesnotalwayscoincidewiththecenterfrequencyoftheoscillator,andsometimesitwilldeviateseverely.Thiswillinevitablycauseadecreaseinreliabilityandsensitivity.Therefore,measuresshouldbetakentomakethetwocenterscoincideasmuchaspossible.ThecircuitshowninFigure4canminimizethefrequencyoffsetofthetwocenters.Figure4.CircuitofLM5673.WorkingVoltageofLM567ShouldBeStableThestabilityoftheoperatingvoltageoftheLM567hasafixedresponsetothestabilityofthecenterfrequencyofthetonedecoder.4.AvoidMisoperationWhentheOutputTerminalisPoweredOnLM567outputsalowlevelatthemomentwhenthepoweristurnedon.Therefore,forsomeremotecontrolcircuits,itisnecessarytoaddaCRintegrationdelaycircuittotheoutputendtoavoiderroneousoperationwhenthepoweristurnedon.Thisisespeciallyimportantintheon-offcontrolcircuit.Afterreadingtheblog,haveyoubetterunderstandLM567?Finally,ifyouhaveanyquestionsaboutLM567,pleasedonothesitatetoleaveamessageinthecommentsectionbelow!

MBR1560CT-E3/45-VISHAY

IIntroductionWhentestingenvironmentalprotection,safety,andeconomicindicatorssuchasnoise,accelerationperformance,maximumspeed,andfuelconsumptionofmotorvehicles,itisnecessarytomeasureandcontrolthevehiclespeed.Mostexistingvehiclespeedmeasurementmethodsuseelectronictimingdevicesorstopwatchestomeasurevehicles.Thetimeittakestotravelafixeddistanceandthenfindtheaveragespeed.Generally,theprocessorandthedisplaypartoftheelectronictimingdevicearebasicallythesame,butthespeedsensorpartisdifferent,andthecharacteristicsofthesensordirectlyaffecttheaccuracyofthemeasurementresult.Atpresent,thecommonlyusedspeedsensorsincludepressuresensitivesensors,COMScamerasandparallellightsources.Theformerhasasimplestructure,butitiscumbersometolay,thesensoriseasilydamaged,andthesensitivityisreducedafterlong-termuse,whichaffectsthemeasurementresults.Thelatterhashighsensitivityandaccuratemeasurement.However,thecostistoohigh,involvesmoreequipment,andhashigherrequirementsfortheplacementofthelightsource.Consideringtheaboveproblems,itisafeasiblemethodtodesignanewinfraredspeedsensorusingLM567.Thesensorissmallinsize,lowincost,simpleinoperation,easytouse,hashighsensitivity,accuracy,stabilityandanti-interferenceability,andissuitableformeasuringtheaveragespeedofavehiclewithinafixeddrivingdistance.Figure1.LM567CatalogIIntroductionIIWorkingPrincipleofTraditionalSpeedMeasuringDevice2.1UsingPressureBeltRoadTester2.2UsingLaserRoadTesterIIIWorkingPrincipleofInfraredSpeedSensorBasedonLM5673.1InternalStructureandFunctionofLM5673.2PrincipleofInfraredSpeedMeasurementBasedonLM567IVConclusionOrdering&QuantityIIWorkingPrincipleofTraditionalSpeedMeasuringDeviceThefollowingusesthemeasurementofmotorcycleaccelerationnoiseasanexample,tointroducetheprinciplesandadvantagesdisadvantagesoftheconventionalspeedmeasuringdevicescurrentlycommonlyused.Figure1isasimplifiedlayoutofmotorcycleaccelerationnoisetest.2.1UsingPressureBeltRoadTesterForthespeedmeasurementmethodusingthepressurebeltroadtester,placethepressurebeltatAA,BB,CC,DDrespectivelyandstickthepressurebelttotheroadsurfacewell.ThedistancebetweenAAandBB,CCandDD(thatis,thespeedmeasurementzone)is1meter,andthepressurebeltandtheroadtesterareconnectedinsequencewithacable.WhenthevehiclepassesthepressurebeltatAA,thepressure-sensitivesensorinthepressurebeltistriggered,andthetriggersignalissenttotheroadtestertostartthetimingofitsinternaltimingdevice;WhenthevehiclepassesBB,atriggersignalisgeneratedagaintostopthetimingdevice.Usingtheinternalprocessoroftheroadtester,thetimetakentopassthedistancebetweenAAandBBisconvertedintovehiclespeedanddisplayedontheLCDscreen.Figure2.LayoutDiagramUsingPressureBeltRoadTesterSimilarly,avehiclespeedvaluecanbemeasuredbetweenCCandDDtomeettherequirementsofnoisemeasurement.Theworkingprincipleofthisspeedmeasurementmethodissimple,buttheequipmentismoretroublesometolay,andthesensoriseasilydamaged.Afterlong-termuse,thesensitivitywillbereduced,whichwillaffectthemeasurementresult.2.2UsingLaserRoadTesterForthespeedmeasurementmethodusingthelaserroadtester,fourparallellaserlightsourcesareplacedatfourpositionsofA,B,C,andD,andfourareplacedatfourpositionsofABCD.CMOScameraforreceivinglasersignals.Thelightsourcecanbeadjustedsothatthelaserlightemittedisalignedwiththecenterofthecamera,andthecameraisconnectedtotheroadtesterinsequence.WhenthevehiclepassesAA,thelightisblocked,andthecamerageneratesatriggersignaltomaketheinternaltimingdeviceoftheroadtesterwork;WhenthevehiclepassesBB,atriggersignalisgeneratedagaintostopthetimingdevice,andtheinternalprocessoroftheroadtesterisusedtoconvertthetimespentthroughthedistancebetweenAAandBBtothevehiclespeedanddisplayitontheLCDscreen.on.Figure3.LayoutDiagramUsingLaserRoadTesterSimilarly,aspeedvaluecanbemeasuredbetweenCCandDD.Thesensitivityandmeasurementaccuracyofthisspeedmeasurementmethodareveryhigh,buttheoperationisextremelyinconvenient.Notonlydoeseachlaserlightsourcerequireanindependentpowersupply,butalsothelasersignalmustbedirectedtothecenterreceivingpointofthecamera,whichplaceshighrequirementsontheplacementofthelightsource,otherwisethesensorwillbedifficulttoworkproperly.IIIWorkingPrincipleofInfraredSpeedSensorBasedonLM567Thisblogusesaphase-lockedloopaudiodecodingchipLM567todesignanewinfraredspeedsensor.Itscircuitdiagramandworkingprincipleareasfollows.3.1InternalStructureandFunctionofLM567LM567isspeciallyusedtodemodulateasingletonefrequencymodulationsignal,anditsoperatingfrequencycanbeashighas500kHz.Itiswidelyusedinindustrialautomaticcontrol,remotecontroltelemetry,securityalarmandotherfields.LM567ismainlycomposedofquadraturephasedetector,phase-lockedloopandamplifier.ItsinternalstructureisshowninFigure2.Pins5and6ofLM567areexternallyconnectedwithtimingresistorsandcapacitorsR,C.RandCdeterminethecenterfrequencyf0ofthephase-lockedloopinternalvoltagecontrolledoscillator,thatis,f0.ResistorRisconnectedbetweenpins5and6,ofwhichpin6isgroundedthroughcapacitorC(Uss).IfRis2~20k,theLM567canextractthetonesignalintherangeof0.01~500kHz.Pins1and2ofLM567arerespectivelyconnectedtothegroundwithacapacitortoformanoutputfilternetworkandaphase-lockedlooplow-passfilternetwork.ThecapacityoftheexternalcapacitorC2onpin2determinesthecapturebandwidthofthephase-lockedloop,anditssizeisBw1070.Uinistheeffectivevalueofthesinewavesignalvoltageinputfrompin3,andrequiresUin25mV,generallybetween100~200mV.TheexternalcapacitorC1ofpin1istheoutputfiltercapacitorofthequadraturephasedetector,anditscapacityismorethantwicethecapacityofthecapacitorC2connectedtopin2,whichshouldsatisfyC12C2.Figure4.TopViewofLM567(1)UsingLM567asFrequencyModulatorPin2isconnectedtotheinputofthelow-passfilterofthephase-lockedloop.Themodulatedsignaladdedfrompin2isfilteredbyalow-passfiltertoremoveout-of-bandnoiseandnoise,andthenaddedtothecenterfrequencyf0ofthevoltage-controlledoscillatorforfrequencymodulation,andthenthepin5outputstheFMsignal.Thecenterfrequencyf0oftheFMsignalisdeterminedbytheparametersoftheRCresistor-capacitornetworkconnectedtopins5and6.WhenLM567isusedasthefrequencymodulationcircuit,onlyitsinternalphase-lockedlooplow-passfilterandvoltage-controlledoscillatorareused.ChangingtheparametervalueoftheRCnetworkcanrealizemodulationtodifferentfrequencies.(2)UsingLM567asFrequencyDemodulatorThemodulatedsignalisinputfrompin3.Whenthecenterfrequencyoftheinputsignalisequaltothecenterfrequencyf0ofthevoltage-controlledoscillatorintheLM567,thelow-passfilter(pin2)oftheloopoutputsthedemodulatedsignal.3.2PrincipleofInfraredSpeedMeasurementBasedonLM567ThecircuitdiagramoftheinfraredspeedsensorbasedonLM567isshowninFigure3.TheinternaloscillatoroftheLM567providesasquarewavesignaltodrivefourLEDstoemitinfraredlight,anditsfrequencyisdeterminedbyR2andC4.Figure5.CircuitDiagramofInfraredSpeedSensorPlacethefoursensorsinthefourpositionsA,B,C,andDinFigure1.Whenthevehiclepassesthesensor,theinfraredraysemittedbytheLEDarereflectedbythevehiclebody.ThephotosensitivetubeQ1receivesthereflectedlight,isamplifiedbythetransistorandconvertedintoavoltagesignal,andissenttotheinternalphasedetectoroftheLM567forsynchronousdemodulation,andthenconvertedintoadigitalsignalbythecomparatorinsidetheLM567andoutputfrompin8.Theoutputsignalistransmittedtotheroadtester,whichtriggersthetimingdeviceintheroadtestertostarttiming.Similarly,whenthevehiclepassesthesensoratpointB,atriggersignalisgeneratedtostopthetimingdeviceandpasstheroadtester.TheinternalprocessoroperatestoobtainthespeedofthevehicleasitpassesAAandBB.LM567isaphase-lockedloopaudiodecodingcircuit.Inthecircuit,itisusedforfrequencyselection,thatis,thecircuitoutputslowlevelonlywhenthefrequencyofthe3-pininputsignalisconsistentwiththefrequencyoftheLM567internaloscillator,otherwisetheoutputishigh.Level.Inotherwords,onlywhenthereflectedinfraredlightreceivedbyQ1comesfromtheLEDinitsowncircuit,theLM567willoutputatriggersignalfromhightolowtotheroadtester.Thebiggestfeatureofthiscircuitistorealizetheautomaticsynchronizationoftheinfraredemissionfrequencyandtheworkingfrequencyofthereceivingcircuit;Thatis,thereisnospecialpulsegeneratingcircuitintheinfraredtransmittingpart,andthepulseisdirectlyintroducedfromthedetectioncircuitofthereceivingpart(LM567phase-lockedcenterfrequencysignal).Inthisway,thewiringanddebuggingworkissimplified,avoidinginconsistenttransmissionandreceptionfrequenciescausedbychangesinthesurroundingenvironmentandcomponentparameters,eliminatingmutualinterferencebetweenadjacentsensors,andgreatlyenhancingcircuitstabilityandanti-interferencecapabilities.IVConclusionTheinfraredspeedsensordesignedbasedontheLM567modulationanddemodulationfunctionrealizestheautomaticsynchronizationoftheinfraredtransmissionfrequencyandtheworkingfrequencyofthereceivingcircuit.Inaddition,ithasthecharacteristicsofstronganti-interferenceabilityandstability,lowcostandsimplestructure.Therefore,itcanbewidelyusedtomeasuretheaveragespeedofvehiclessuchasautomobilesandmotorcycles.Figure6.LM567Afterreadingtheblog,haveyoubetterunderstandLM567?Finally,ifyouhaveanyquestionsaboutLM567,pleasedonothesitatetoleaveamessageinthecommentsectionbelow!

TheLM2940isacommonlow-dropout(LDO)linearregulator.ThisisacomprehensiveintroductiontoLM2940voltageregulator,fromitspinout,feature,parametertoitsapplication,itsdifferencebetweenLM7805andmore.CatalogLM2940DescriptionLM2940PinoutLM2940FeaturesLM2940ParametersLM2940EquivalentLM2940VSLM7805LM2940TypicalApplicationLM2940PackageLM2940ApplicationComponentDatasheetLM2940DescriptionTheLM2940isacommonlow-dropout(LDO)linearregulator.Thedropoutvoltageofaregulatoristhevoltagerequiredbetweentheinputandtheregulatedoutputvoltage.Theregulatorwastesthisvoltage(multipliedbycurrent),sothelowerthedropoutonalinearregulator,themoreefficientitis.ThismeansthattheLM2940,witha5Vdropoutat1amp,canbeusedwitha6voltwallwarttoprovidearegulated5Voutput.Thisalsomeansthattheregulatorwilloperateatamuchlowertemperaturethanastandard7805,whichwouldrequireamuchhigherinputvoltage(around7.5volts)foraregulated5Voutput.LM2940PinoutLM2940voltageregulatorLM2940PinoutPinNo.PinNameDescription1VinA(+ve)voltageisgivenasinputtothispin.2GNDCommontobothInputandOutput.3VoutOutputregulated12VistakenatthispinoftheIC.LM2940FeaturesInputVoltageRange=6Vto26VDropoutVoltageTypically0.5VatIOUT=1AOutputCurrentinExcessof1AOutputVoltageTrimmedBeforeAssemblyReverseBatteryProtectionInternalShortCircuitCurrentLimitMirrorImageInsertionProtectionP+ProductEnhancementTestedLM2940ParametersOutputoptionsFixedOutputIout(Max)(A)1Vin(Max)(V)26Vin(Min)(V)6Vout(Max)(V)15Vout(Min)(V)5Fixedoutputoptions(V)5,8,9,10,12,15Noise(uVrms)150Iq(Typ)(mA)10ThermalresistanceJA(C/W)23Loadcapacitance(Min)(F)22RatingCatalogRegulatedoutputs(#)1Features-Accuracy(%)2PSRR@100KHz(dB)48Dropoutvoltage(Vdo)(Typ)(mV)500Operatingtemperaturerange(C)-40to125,-40to85LM2940EquivalentTheequivalentforLM2940isLM7805.LM2940VSLM7805TheLM7805isapopularlinearvoltageregulatorbecauseitrequiresnoadditionalcomponentstooperate.Itisaverylow-costcomponent.Becauseofitscharacteristics,itreducestheoutputvoltageattheexpenseofheatdissipation,makingitinefficient.TheLM7805requiresaminimuminputvoltageof7.3Vtofunctionproperly.Itcanhandleamaximumcurrentof1A.Somemodelscanhandleupto1.5A.Itisrecommended,andinsomecasesrequired,tousecapacitorstoreduceoreliminatetheeffectsofthefrequenciesintroducedbytheotherelementsofthecircuit.Theyalsohelptoreducetheimpactofpeakconsumption.WhiletheLM2940isfromadifferentgeneration,butitspinisstillcompatiblewiththeLM7805.ItisaLow-dropout(LDO)LinearRegulatorthatismoreefficientthantheLM7805,butitwillrequirecapacitors.ThemaindifferencebetweenLM2940andLM7805isthatthemaximumoutputcurrentofLM2940is1A.ThemaximumoutputcurrentofLM7805is1.5A.Othersareveryclose,soifthecircuitonlyrequires1Aorbelow,LM2940canbeusedinsteadofLM7805.Whatsmore,the7805isexpendingtheexcesspowerasheat.Whichisverylossyespecialyifyourprojectusesbatteries.Theotherchipisabuckconverterissoitapproaches90%efficiencybyswitchingsothereisnowasteheat,thatswhyeventhoughLM7805ischeaperandeasiertousebuttheresstillalotofpeoplewouldgoforLM2940.LM2940LM7805SchematicComparisonLM2940SchematicLM7805SchematicLM2940TypicalApplicationLM2940PackageLM2940ApplicationPostregulatorforswitchingsuppliesLogicpowerSuppliesIndustrialInstrumentationComponentDatasheetLM2940DatasheetIDescriptionThisblogintroducesapulsewidthmodulationtechnologywithTL494asthecontrolcore.AnditisappliedtoDCmotorcontrolsystem.Theworkingprincipleofthesystem,therealizationcircuitandthestructureandspecificapplicationofthePWMcontrolchipareanalyzedindetail.CatalogIDescriptionIIWorkingPrincipleandRealizationofControlSystem2.1HowSystemWorks2.2SelectionofPWMControlChip2.3RealizationCircuitofSystemIIISimulationResultsIVConclusionFAQOrdering&QuantityIIWorkingPrincipleandRealizationofControlSystem2.1HowSystemWorksThebasicdesignideaofthiscontrolsystemistouseastep-downchoppercircuitasshowninFigure1.Figure1.Step-downChopperCircuitanditsWaveformInthefigure,theDCpowersupplyisUd,andtheloadisamotor(M).Whentheswitchingdevice(VT)istriggeredandturnedon,theDCvoltageisappliedtothemotorforadurationoft1.Whenthefieldswitchingdeviceisturnedoff,thevoltageontheloadiszeroandlastsfort2time.IfwedefinethedutycycleT=t1+t2,andthedutycyclek=t/T,thewaveformdiagramandtheprincipleoftheDCchoppercircuitareasfollows:Theaveragevalue(Uo)ofthesystemoutputvoltageis:Theeffectivevalue(U)ofitsoutputvoltageis:Thepulsewidthmodulation(PWM)workingmodeadoptedbythissystemkeepsTunchangedandt1changes.TheprincipleblockdiagramofthecontrolsystemisshowninFigure2.Figure2.ControlSystemBlockDiagramThepowersupplyinthissystemmakesthemotorworkthroughthepowerdrivecircuit.Theon-offofthepowerdrivecircuitiscontrolledbythePWMcontrolchip.ThesystemsamplesthemotorcurrentfeedsitbacktothePWMcontrolchipandcomparesitwiththecurrentvalueofthecurrentcomparisoncircuit.TocontrolthePWMsignaloutputtoachievethepurposeofspeedregulation.ThesystemalsosamplesthepowersupplyvoltageandfeedsitbacktothePWMcontrolchip.Inthisway,itcanbecomparedwiththevoltagevalueofthevoltagecomparisoncircuittocontrolthePWMsignaloutputandachievetheeffectofUndervoltageprotection.WeusethecommonBUCKcircuitforthepowerdrivecircuitandPowerMOSFETfortheswitchtube.Theregulationofitsoutputvoltageisrealizedbycontrollingtheturn-ontimeofthedevice.Consideringtheinfluenceoftheinductanceofthemotor,theoutputcurrentisrelativelystableandtheenergyconsumptionislow.2.2SelectionofPWMControlChipInthecontrolcircuitofthemotorPWMcontrolsystem,theTL494chipisselected.TL494chiphasthefeaturesofstronganti-interferenceability,simplestructure,highreliabilityandlowprice.TheinternalcircuitofTL494(Figure3)consistsofthefollowingparts:Thereferencevoltagegeneratingcircuit;Oscillationcircuit;Intermittentadjustmentcircuit;Twoerroramplifiers;Pulsewidthmodulationcomparator;Outputcircuit;...Figure3.TL494InternalStructureAmongthem:Forpins1and2,theyarethenon-invertingandinvertinginputterminalsoferroramplifier1.Forpin3,itisphasecorrectionandgainscontrol.Forpin4,itisanintermittentperiodofconditioning,andthecut-offtimecanbechangedfrom2%to100%whenavoltageof0~3.3Visappliedtoit.Forpins5and6,theyareusedtoconnectexternaloscillationresistorRTandoscillationcapacitorCTtodeterminethefrequencyfoscofthesawtoothwavegeneratedbytheoscillator.Where:ThevaluerangeofRTandCT:RT=5~100kQ,CT=0.001~0.1F.Pin7isthegroundterminal;Forpins8,9and11,10,theyarethecollectorandemitterofthetwofinaloutputtransistorsinsideTL494;For12feet,itisthepowersupplyterminal;Forpin13,itistheoutputcontrolterminal.Whenthispinisgrounded,itisaparallelsingle-endedoutputmode.Whenpin14isconnected,itisapush-pulloutputmode;For14feet,itisthe5Vreferencevoltageoutputterminal,themaximumoutputcurrentis10mA;For15and16pins,theyaretheinvertingandnon-invertinginputterminalsoftheerroramplifier2.2.3RealizationCircuitofSystemTheconcreterealizationcircuitofthiscontrolsystemisshowninFig.4.Thesystemusescurrentnegativefeedbacktotrackthespeedofthemotor.Atthesametime,throughthenegativefeedbackofthevoltageofthepowersupply,thesystemhasthefunctionofundervoltageprotection.Figure4.SystemImplementationCircuitThemotorcurrentisdetectedandfedbacktopin1oftheerroramplifier1oftheTL494,comparedwiththecurrentreferencesignalofpin2tocontrolthePWMoutputofTL494.Soastorealizethefunctionofregulatingthespeedofthemotor.Byadjustingtheresistancevalueoftheadjustableresistor(RES1).Thatis,changethesizeofthesetcurrentreferencesignaltoadjustthedutycycleofthePWMoutputsignal.Soastoachievethepurposeofadjustingthemotorspeed.Bysamplingthevoltageofthepowersupply,itisfedbacktopin15oftheinternalerroramplifier2ofTI494.Thencomparewiththevoltagereferencesignalofpin16tocontrolthePWMoutputofTL494.Soastorealizetheundervoltageprotectionfunctionofthesystem.ThesystempowerisdrivenbyPowerMOSFET,whichhasahighinputimpedanceandcanbedirectlydrivenbyatransistor.Pin13ofTI494isusedtocontroltheoutputmode.Inthissystem,choosetoinputthisendaslowlevel.Atthistime,theflip-flopsQ1andQ2intheTL494donotwork,thetwooutputsarethesame,thefrequencyisthesameastheoscillatorfrequency,andthemaximumdutycycleis98%.IIISimulationResultsInordertoverifytheeffectivenessofthesystem,wecansimulatethecircuitoftheabove-mentionedDCmotorcontrolsystembasedonPWMtechnologybycomputer.WesetthesystemspowersupplyvoltageUcc=12V,DCmotorratedparameters:Un=12V,In=15A,4poles,armatureresistanceRa=0.21Q,momentofinertiaJ=0.57kg㎡.ThroughchangingtheadjustableresistanceRES1ofthecontrolcircuittorealizethedifferentdutyratioofthesystemoutput.Whentheoutputdutyratiois0.2,0.65/0.8,thevoltageandcurrentwaveformsofthemotorareshowninFigure5.Figure5.MotorVoltageandCurrentWaveformItcanbeseenfromFigure5thatwhenoutputtingdifferentdutyratios,thevoltageandcurrentwaveformsofthemotorarestable,whichisconducivetothelong-termstableoperationofthemotor.ThisshowsthattheTL494-basedPWMcontroltechnologyintroducedinthisarticleisfeasibleinpracticalapplicationsandrunsstably.IVConclusionThisblogsummarizesaPWMcontroltechnologybasedontheTL494chip.Thesimulationresultsshowthatthesystemhasasimplestructure,lowenergyconsumption,andstableoperation.AndthecharacteristicsoftheTL494chiphavebeenfullyutilizedsothatthesystemhastheadvantagesofundervoltageprotection.FAQWhatisTL494?TL494isaPWMcontrollerICusedforpowerelectronicscircuits.Itcomprisesofon-chiptwoerroramplifiersanoscillatorwithadjustablefrequencyfeature,anoutputflip-flophavingpulsesteeringcontrol,andanoutputcontrolcircuitwithfeedback.WhatisthedetaileddescriptionofTL494?TheTL494deviceincorporatesallthefunctionsrequiredintheconstructionofapulse-width-modulation(PWM)controlcircuitonasinglechip.Designedprimarilyforpower-supplycontrol,thisdeviceofferstheflexibilitytotailorthepower-supplycontrolcircuitrytoaspecificapplication.TheTL494devicecontainstwoerroramplifiers,anon-chipadjustableoscillator,adead-timecontrol(DTC)comparator,apulse-steeringcontrolflip-flop,a5-V,5%-precisionregulator,andoutput-controlcircuits.Theerroramplifiersexhibitacommon-modevoltagerangefrom0.3VtoVCC2V.Thedead-timecontrolcomparatorhasafixedoffsetthatprovidesapproximately5%deadtime.Theon-chiposcillatorcanbebypassedbyterminatingRTtothereferenceoutputandprovidingasawtoothinputtoCT,oritcandrivethecommoncircuitsinsynchronousmultiple-railpowersupplies.Theuncommittedoutputtransistorsprovideeithercommon-emitteroremitter-followeroutputcapability.TheTL494deviceprovidesforpush-pullorsingle-endedoutputoperation,whichcanbeselectedthroughtheoutput-controlfunction.Thearchitectureofthisdeviceprohibitsthepossibilityofeitheroutputbeingpulsedtwiceduringpush-pulloperation.WhatareTL494productfeatures?CompletePWMPower-ControlCircuitryUncommittedOutputsfor200-mASinkorSourceCurrentOutputControlSelectsSingle-EndedorPush-PullOperationInternalCircuitryProhibitsDoublePulseatEitherOutputVariableDeadTimeProvidesControlOverTotalRangeWhatisPWMIC?TheTL494fixedfrequencyPWMControllercanbeusedforDCtoDCconversionregardlessofbuckorboosttopology....ThisICfeatureanoutputcontrolcircuit,aflipflop,adeadtimecomparator,twodifferenterroramplifiers,a5Vreferencevoltage,anoscillator,andaPWMcomparator.HowdoesPWMICwork?Asitsnamesuggests,pulsewidthmodulationspeedcontrolworksbydrivingthemotorwithaseriesofON-OFFpulsesandvaryingthedutycycle,thefractionoftimethattheoutputvoltageisONcomparedtowhenitisOFF,ofthepulseswhilekeepingthefrequencyconstant.WhichICisbetterforabuckconverter,TL494orUC3843?TheymainlydifferintypeofcontrolTL494=voltagemodecontrol(Oneloopcontrol).whileUC3843usescurrentmodecontrol(Nestedloopcontrol,withainner/fastcurrentloopandanotherouter/slowervoltageloop)Typicallyvoltagemodeareusedinmultipleoutputconverterswithgoodcross-regulation.CurrentmodewhenyouwanttoparallelmultipleconverterstomakeasingleconverterwithhighercurrentratingTL494isaverypopularIC.IfyouhavesimplerequirementsTL494isrecommendedHowdoIproperlysetthefeedbackpinonaTL494SMPSIC?Thefeedbackpinistheoutputofbotherroramplifiers,usedincomparingandadjustingtheoutputpulsewidthtotheDCcontrolvoltage.OnvariouscircuitsIhavelookedup,theop-ampconnectedtopins23areusedtosetthegainofthefeedbackloop,using2resistorswithoneresistorconnectingto2.5Vpotentialdivideron5Vreferencevoltage.Withtheotherconnectingtotheoutput(viasuitableisolation)Thegainappearstobesetat101,usinga51kfeedbackwith510ohmstothe2.5Vreference.Itisusedtocontrolthegainofthefeedbackvoltage.NoliteratureIhaveyetfound,givesanindicationonhowthisgainbeset,exceptagraphshowinganopenloopgainof1000,presumablythegainissetforthebeststability,althoughtherewillalsobeatimeconstant.WhyistherenofrequencycompensationrequiredinTIsTL494examplebuckregulatordesign(operationalamplifier,buckphase,shiftphase,margin,TL494,electronics)?ItsafixedfrequencyPWMcontrollerwithinternaldeadtimetimer.Frequencycompensationisnotrequired.Takealookatthedatasheet.HowtouseTL494?

DescriptionTL494wasdesignedandlaunchedbyTexasInstrumentsintheearly1980s.Itwaswidelyacceptedbythemarketimmediatelyafteritwaslaunched,especiallyontheATXhalf-bridgepowersupplyofPCs.Untiltoday,aconsiderableproportionofPCpowersuppliesarestillbasedontheTL494chip.HowtoTestTL494NCatalogDescriptionComponentDatasheetTL494PinoutTL494ParameterFeaturesAdvantagesApplicationsTL494SimplifiedBlockDiagramTL494PackageandPinsFunctionalBlockDiagramWheretouseTL494HowtouseTL494TL494TypicalApplicationFAQOrdering&QuantityComponentDatasheetDatasheetTL494Pulse-Width-ModulationControlCircuitsdatasheet(Rev.H)Applicationnotes1IsolatedMultipleOutputFlybackConverterDesignUsingTL494Applicationnotes2DesigningSwitchingVoltageRegulatorsWiththeTL494(Rev.E)TL494PinoutPinDescriptionNameNO.1IN+1Noninvertinginputtoerroramplifier11IN2Invertinginputtoerroramplifier12IN+16Noninvertinginputtoerroramplifier22IN-15Invertinginputtoerroramplifier2C18CollectorterminalofBJToutput1C211CollectorterminalofBJToutput2CT5CapacitorterminalusedtosetoscillatorfrequencyDTC4Dead-timecontrolcomparatorinputE19EmitterterminalofBJToutput1E210EmitterterminalofBJToutput2FEEDBACK3InputpinforfeedbackGND7GroundOUTPUTCTRL13Selectssingle-ended/paralleloutputorpush-pulloperationREF145-VreferenceregulatoroutputRT6ResistorterminalusedtosetoscillatorfrequencyVCC12PositiveSupplyTL494ParameterTopologyBoost,Buck,Flyback,Forward,Full-Bridge,Half-Bridge,Push-PullControlmethodVoltageVCC(Min)(V)7VCC(Max)(V)40Dutycycle(Max)(%)45UVLOthresholdson/off(V)Frequency(Max)(kHz)300Operatingtemperaturerange(C)-40to85,0to70Gatedrive(Typ)(A)0.2FeaturesAdjustableSwitchingFrequency,DeadTimeControl,ErrorAmplifier,Multi-topologyRatingCatalogFeaturesCompletePWMPower-ControlCircuitryUncommittedOutputsfor200-mASinkorSourceCurrentOutputControlSelectsSingle-EndedorPush-PullOperationInternalCircuitryProhibitsDoublePulseatEitherOutputVariableDeadTimeProvidesControlOverTotalRangeInternalRegulatorProvidesaStable5-VReferenceSupplyWith5%ToleranceCircuitArchitectureAllowsEasySynchronizationAdvantagesTheTL494deviceincorporatesallthefunctionsrequiredintheconstructionofapulse-width-modulation(PWM)controlcircuitonasinglechip.Designedprimarilyforpower-supplycontrol,thisdeviceofferstheflexibilitytotailorthepower-supplycontrolcircuitrytoaspecificapplication.TheTL494devicecontainstwoerroramplifiers,anon-chipadjustableoscillator,adead-timecontrol(DTC)comparator,apulse-steeringcontrolflip-flop,a5-V,5%-precisionregulator,andoutput-controlcircuits.Theerroramplifiersexhibitacommon-modevoltagerangefrom0.3VtoVCC2V.Thedead-timecontrolcomparatorhasafixedoffsetthatprovidesapproximately5%deadtime.Theon-chiposcillatorcanbebypassedbyterminatingRTtothereferenceoutputandprovidingasawtoothinputtoCT,oritcandrivethecommoncircuitsinsynchronousmultiple-railpowersupplies.Theuncommittedoutputtransistorsprovideeithercommon-emitteroremitter-followeroutputcapability.TheTL494deviceprovidesforpush-pullorsingle-endedoutputoperation,whichcanbeselectedthroughtheoutput-controlfunction.Thearchitectureofthisdeviceprohibitsthepossibilityofeitheroutputbeingpulsedtwiceduringpush-pulloperation.TheTL494Cdeviceischaracterizedforoperationfrom0Cto70C.TheTL494Ideviceischaracterizedforoperationfrom40Cto85C.ApplicationsDesktopPCsMicrowaveOvensPowerSupplies:AC/DC,Isolated,WithPFC,90WServerPSUsSolarMicro-InvertersWashingMachines:Low-EndandHigh-EndE-BikesPowerSupplies:AC/DC,Isolated,NoPFC,90WPower:Telecom/ServerAC/DCSupplies:DualController:AnalogSmokeDetectorsSolarPowerInvertersTL494SimplifiedBlockDiagramTL494PackageandPinsPackagePinsSizePDIP(N)16181mm19.3x9.4SOIC(D)1659mm9.9x6SOP(NS)1680mm10.2x7.8TSSOP(PW)1622mm4.4x5FunctionalBlockDiagramWheretouseTL494TheTL494fixedfrequencyPWMControllercanbeusedforDCtoDCconversionregardlessofbuckorboosttopology.TL494canbeusedtoprovideaconstantcurrentbyvaryingtheoutputvoltagetotheload.ThisICfeatureanoutputcontrolcircuit,aflipflop,adeadtimecomparator,twodifferenterroramplifiers,a5Vreferencevoltage,anoscillator,andaPWMcomparator.SoifyouarelookingforanICtoproducePWMsignalsforcontrollingapowerswitchbasedonthecurrentflowingthroughthecircuit,thenthisICmightbetherightchoiceforyou.HowtouseTL494AtestcircuitfromtheTL494datasheetisshownbelow.NoninvertingpinsareconnectedtotheRefpinwhileinvertingpinsareconnectedtotheground.TestinputsaregiventoDTCandFEEDBACKpins.Externalcapacitorandresistorareconnectedtopin56tocontroltheoscillatorfrequency.Theerroramplifiercomparesasampleofthe5-VoutputtothereferenceandadjuststhePWMtomaintainaconstantoutputcurrentTL494TypicalApplicationSwitchingandControlSectionsInputPowerSourceError-AmplifierSectionCurrent-LimitingCircuitSoft-StartCircuitSwitchingCircuitPower-SwitchSectionFAQWhatisTL494?TL494isaPWMcontrollerICusedforpowerelectronicscircuits.Itcomprisesofon-chiptwoerroramplifiersanoscillatorwithadjustablefrequencyfeature,anoutputflip-flophavingpulsesteeringcontrol,andanoutputcontrolcircuitwithfeedback.WhatisthedetaileddescriptionofTL494?TheTL494deviceincorporatesallthefunctionsrequiredintheconstructionofapulse-width-modulation(PWM)controlcircuitonasinglechip.Designedprimarilyforpower-supplycontrol,thisdeviceofferstheflexibilitytotailorthepower-supplycontrolcircuitrytoaspecificapplication.TheTL494devicecontainstwoerroramplifiers,anon-chipadjustableoscillator,adead-timecontrol(DTC)comparator,apulse-steeringcontrolflip-flop,a5-V,5%-precisionregulator,andoutput-controlcircuits.Theerroramplifiersexhibitacommon-modevoltagerangefrom0.3VtoVCC2V.Thedead-timecontrolcomparatorhasafixedoffsetthatprovidesapproximately5%deadtime.Theon-chiposcillatorcanbebypassedbyterminatingRTtothereferenceoutputandprovidingasawtoothinputtoCT,oritcandrivethecommoncircuitsinsynchronousmultiple-railpowersupplies.Theuncommittedoutputtransistorsprovideeithercommon-emitteroremitter-followeroutputcapability.TheTL494deviceprovidesforpush-pullorsingle-endedoutputoperation,whichcanbeselectedthroughtheoutput-controlfunction.Thearchitectureofthisdeviceprohibitsthepossibilityofeitheroutputbeingpulsedtwiceduringpush-pulloperation.WhatareTL494productfeatures?CompletePWMPower-ControlCircuitryUncommittedOutputsfor200-mASinkorSourceCurrentOutputControlSelectsSingle-EndedorPush-PullOperationInternalCircuitryProhibitsDoublePulseatEitherOutputVariableDeadTimeProvidesControlOverTotalRangeWhatisPWMIC?TheTL494fixedfrequencyPWMControllercanbeusedforDCtoDCconversionregardlessofbuckorboosttopology....ThisICfeatureanoutputcontrolcircuit,aflipflop,adeadtimecomparator,twodifferenterroramplifiers,a5Vreferencevoltage,anoscillator,andaPWMcomparator.HowdoesPWMICwork?Asitsnamesuggests,pulsewidthmodulationspeedcontrolworksbydrivingthemotorwithaseriesofON-OFFpulsesandvaryingthedutycycle,thefractionoftimethattheoutputvoltageisONcomparedtowhenitisOFF,ofthepulseswhilekeepingthefrequencyconstant.WhichICisbetterforabuckconverter,TL494orUC3843?TheymainlydifferintypeofcontrolTL494=voltagemodecontrol(Oneloopcontrol).whileUC3843usescurrentmodecontrol(Nestedloopcontrol,withainner/fastcurrentloopandanotherouter/slowervoltageloop)Typicallyvoltagemodeareusedinmultipleoutputconverterswithgoodcross-regulation.CurrentmodewhenyouwanttoparallelmultipleconverterstomakeasingleconverterwithhighercurrentratingTL494isaverypopularIC.IfyouhavesimplerequirementsTL494isrecommendedHowdoIproperlysetthefeedbackpinonaTL494SMPSIC?Thefeedbackpinistheoutputofbotherroramplifiers,usedincomparingandadjustingtheoutputpulsewidthtotheDCcontrolvoltage.OnvariouscircuitsIhavelookedup,theop-ampconnectedtopins23areusedtosetthegainofthefeedbackloop,using2resistorswithoneresistorconnectingto2.5Vpotentialdivideron5Vreferencevoltage.Withtheotherconnectingtotheoutput(viasuitableisolation)Thegainappearstobesetat101,usinga51kfeedbackwith510ohmstothe2.5Vreference.Itisusedtocontrolthegainofthefeedbackvoltage.NoliteratureIhaveyetfound,givesanindicationonhowthisgainbeset,exceptagraphshowinganopenloopgainof1000,presumablythegainissetforthebeststability,althoughtherewillalsobeatimeconstant.WhyistherenofrequencycompensationrequiredinTIsTL494examplebuckregulatordesign(operationalamplifier,buckphase,shiftphase,margin,TL494,electronics)?ItsafixedfrequencyPWMcontrollerwithinternaldeadtimetimer.Frequencycompensationisnotrequired.Takealookatthedatasheet.HowtouseTL494?I.DesriptionInthefieldofmeasurementandcontrol,itisoftenencounteredthattheoutputsignalofthemonitoredobjectissmall,anditisdifficulttodirectlycollectit.Generally,itneedstobeamplifiedbeforeprocessing.Thisarticleintroducesamethodofimplementingasmallsignalacquisitionsystem.Thesmallestsystemisrealizedbyusingthesingle-chipSTC25A60S2withA/Dconversionfunctionandtheeasy-to-useamplifierAD620withpreciseamplificationfunction.Thesystemdesignandimplementationarediscussedandtheacquisitionisintroducedindetail.Theprocessofsmallsignal,andgivespracticalapplicationexamples,aswellastheapplicationofsmallsignalacquisitioninrelatedfields.AD620CatalogI.DesriptionII.AD620IntroductionIII.IntroductiontoSTC12C5A60S2IV.SystemHardwareDesign4.1SystemPrincipleBlockDiagram4.2PowerSupplyCircuitDesign4.3SignalConditioningCircuit4.4SystemDecouplingCircuit4.5RealizationofA/DConversion4.6Follow-upWorkV.PracticalApplicationVI.ConclusionFAQOrdering&QuantityII.AD620IntroductionAsamonolithicinstrumentamplifier,AD620haslowpowerconsumption,achipwithhighgainthroughexternalresistors,andfeatureslowinputdriftandtemperaturedrift.AD620isdevelopedfromthetraditionalthreeoperationalamplifiers,butsomeofthemainperformanceisbetterthanthedesignoftheinstrumentamplifiercomposedofthreeoperationalamplifiers,suchaswidepowersupplyrange(2.3~18V),smalldesignvolume,andverypowerconsumptionLow(themaximumpowersupplycurrentisonly1.3mA),soitissuitableforlow-voltage,low-powerapplications.Figure1SchematicdiagramofAD620principleThemonolithicstructureandlasercrystaladjustmentofAD620allowcircuitcomponentstobecloselymatchedandtracked,therebyensuringtheinherenthighperformanceofthecircuit.AD620isathree-op-ampintegratedinstrumentationamplifierstructure.Inordertoprotectthehighprecisionofgaincontrol,theinputtransistorprovidesasimpledifferentialbipolarinput,andusestheprocesstoobtainalowerinputbiascurrent.Throughtheinputstageinternalop-ampThefeedbacktokeepthecollectorcurrentoftheinputtransistorconstant,andtheinputvoltageisaddedtotheexternalgaincontrolresistorRG.ThetwointernalgainresistorsofAD620are24.7k8,sothegainequationis:G=49.4k/RG+1(1)Fortherequiredgain,theexternalcontrolresistancevalueis:RG=49.4/(G-1)k(2)III.IntroductiontoSTC12C5A60S2STC12C5A60S2isanewgeneration8051single-chipmicrocomputerwithA/Dconversionfunction.Theinstructioncodeisfullycompatiblewiththetraditional8051,butthespeedis8-12timesfaster.With8channelsofhigh-speed10-bitinputA/Dconversion(250k/s),itcanbeusedfortemperaturedetection,batteryvoltagedetection,keyscanning,spectrumdetection,etc.TheusercansetanychannelasA/Dconversion,andtheportsthatdonotneedtobeusedasA/DcancontinuetobeusedasI/Oports.Itscharacteristicsareasfollows:Figure2STC12C5A60S2(1)On-chipintegrated1280bytesRAM;(2)WithEEPROMfunction(STC12C5A62S2/AD/PWMwithoutinternalEEPROM);(3)Enhanced8051CPU,1T,singleclock/machinecycle,instructioncodeisfullycompatiblewithtraditional8051;(4)InternalintegratedMAX810dedicatedresetcircuit(whentheexternalcrystalisbelow12M,theresetpincanbedirectlyconnectedtothegroundwith1Kresistance);(5)Userapplicationspace8K/16K/20K/32K/40K/48K/52K/60K/62Kbytes;(6)ISP(In-SystemProgrammable)/IAP(In-ApplicationProgrammable),noneedforadedicatedprogrammer,noneedforadedicatedemulator,youcandownloadtheuserprogramdirectlythroughtheserialport(P3.0/P3.1),andonepiececanbecompletedinafewseconds;(7)STC12C5A60S2serieshavedualserialports,onlythosewiththeS2logosuffixhavedualserialports,RxD2/P1.2(canbesettoP4.2byregister),TxD2/P1.3(canbesettoP4.3byregister);(8)GeneralI/Oports(36/40/44),afterreset,theyare:quasi-bidirectionalport/weakpull-up(normal8051traditionalI/Oport),whichcanbesettofourmodes:quasi-bidirectionalport/weakPull-up,push-pull/strongpull-up,onlyinput/highimpedance,open-drain,eachI/Oportdrivecapacitycanreach20mA,butthewholechipshouldnotexceed120mA;(9)A/Dconversion,10-bitprecisionADC,8channelsintotal,conversionspeedupto250K/S(250,000timespersecond),universalfull-duplexasynchronousserialport(UART),becausetheSTC12seriesishigh-speed8051,canreusetimerorPCAsoftwaretorealizemultipleserialports.IV.SystemHardwareDesign4.1SystemPrincipleBlockDiagramGenerallyspeaking,beforethesignalisused,itneedstobefilteredandthenamplified,oramplifiedandthenfiltered,andthenobtained/perceivedbymeanssuchasA/D.Forsmallsignals,thesignalamplitudeisonlyafewmillivoltsorevensmaller.Iffilteredfirst,usefulsignalsmaybefilteredout.Therefore,inthiscase,youneedtoamplifyfirst,thenfilter,andthenperformA/Dconversionorotherprocessing.Accordingtothecharacteristicsofthissystem,theinterferenceinthesystemcanbeignored,sothesignalfilteringlinkisnotconsidered.Therefore,thesystemismainlyrealizedthroughthreeimportantlinks:signalextraction,signalamplification,andA/Dacquisition.Thedatageneratedinthethirdlinkcanguidepeoplesworkordisplayrelevantinformation.TheblockdiagramoftheentiresystemisshowninFigure3.Figure3Systemblockdiagram4.2PowerSupplyCircuitDesignAD620amplifiercanusesinglepowersupplyordualpowersupply,butwhenusingdualpowersupply,itsperformanceisbetterthansinglepowersupply.Inintegratedcircuitdesign,singlepowersupplyiseasytoimplement,butconsideringtheworkingperformanceofthechip,dualpowersupplyisusedinthissystem.UsetheICL7660Schiptoconvertanexternalsinglepowersupplyintoadualpowersupply.ICL7660Sisavoltageconversionchipthatcanrealizethefunctionofconvertingapositivevoltagetoanegativevoltage,anditsperipheralcircuitisrelativelysimple.ThespecificcircuitisshowninFigure4.Figure4PowersupplyimplementationschematicdiagramTheotherchipsinthesystemarepoweredbyasingle5Vpowersupply,andtheconnected5Vpowersupplycanbeusedwithoutanyprocessing,whichisnotdescribedhere.4.3SignalConditioningCircuitTheactualweaksignalisgenerallymVlevelorevensmaller.Beforeprocessing,itneedstobeamplifiedandthenA/Dcollected.AccordingtotheA/DfunctionofSTC12C5A60S2,itisnecessarytoaccuratelyamplifythesignaltoreachtheVlevel,sotheAD620amplifierisused.AD620hasagoodamplificationeffecton2inputdifferentialsignals.Inpracticalapplications,thesignalsaregenerallygeneratedbyelectricbridges.Inordertorealizesignalamplification,AD620needsanexternalresistor,whichdeterminestheamplificationfactortogetherwiththeinternalresistor.SupposethemagnificationisG,thenthereisthefollowingformula.G=(RG/R1)+1(1)canalsobewrittenasthefollowingformula:G=49.4k/RG+1(2)1)Intheformula,RGistheinternalresistanceofAD620,andR1istheexternalresistance.Itcanbeseenfromtheformulas(1)and(2)thatthesizeofRGintheformula(1)is49.4k.Theconditionedsignalisoutputthroughthe6-pinofAD620.Atthistime,itcanbedirectlyconnectedtotheA/Dconversionchiptorealizedatacollection.Itcanbereducedbythecorrespondingmultiplewhenusingit.TheprincipleofsignalconditioningisshowninFigure5.Figure5Signalconditioningcircuit4.4SystemDecouplingCircuitSincethesystemmainlyrealizessmallsignalamplificationandA/Dconversionafteramplification,thechipthatcompletestheA/Dfunctionofthissystem,namelySTC12C5A60S2,usesitsownworkingpowersupplyasthereferencevoltage.Inordertoensuretheconsistencyoftheconversionresults,itisnecessarytoensurethepowersupplyvoltagestability.Tofilterouttheinterferenceinthepowersupply,itcanbefilteredbymultiplecapacitorsinparallel.Afterthecapacitorsareconnectedinparallel,thecapacitancevalueincreases,buttheequivalentresistanceinsidethecapacitorisreducedduetotheparallelconnection,whichisbeneficialtoreducetheloss.Therefore,manycapacitorsareusedinparallel,andtherealizationprincipleisshowninFigure6.Figure6Powerdecouplingcircuit4.5RealizationofA/DConversionAsmentionedearlier,STC12C5A60S2isasingle-chipmicrocomputerwithA/Dconversionfunction,whichisconvenient,simple,andmulti-functional.ItsA/Dconversiononlyrequires90clockcycles(relatedtoitsoperatingfrequency)atthefastest.ThissystemUseittoachieveA/Dconversion.STC12C5A60S2usesportP1asan8-channelA/Dconversioninputinterface.Whenusingit,youonlyneedtosetitasananaloginterface.Bysettingthecorrespondingregister,theA/Dconversioncanbecompleted.Theunusedpinscanstillbeusedasordinarytubes.ThissystemrealizestheA/Dconversionofoneinputsignal,soitonlyneedstosetone.Inthissystem,P1.0portisusedasthesignalinputport.ThissystemrealizestheprincipleofA/DconversionasshowninFigure7.Figure7A/Dacquisitioncircuit4.6Follow-upWorkAftertheA/Dconversioniscompleted,dataanalysisisrequired.Generally,itcanbesenttotheuppercomputerthroughthecommunicationport(usuallyserialport),andthedataisprocessedbytheuppercomputer.Accordingtothedifferentcharacteristicsofthespecificsystem,thedataprocessingmethodsarealsodifferent,soitsnoneedtodiscussthemindetailhere.Table1ADconversiondataandactualdataAfterthesystemperformsA/Dconversiononsignalsofdifferentsizes,aseriesofactualdataandtheoreticaldataareobtained,asshowninTable1.DrawthecurveofA/DdatathroughExcel,andfoundthatthesystemA/Dconverterhasgoodlinearity.AsshowninFigure8.Figure8LinearityofA/DconverterV.PracticalApplicationThesmallsignalconditioning,A/Dconversion,andprocessingmethodsarediscussedinmoredetailabove.Thespecificapplicationisintroducedbelowthroughexamples.Asakindofsensingelement,resistancestraingaugeiscommonlyusedtomonitorthedeformationoftheobject.Generally,thestraingaugeisattachedtothesidepointofthecomponent.Afterthecomponentisstressed,duetothestrainofthemeasuringpoint,theresistancechanges,resultinginaweakvoltagechange.Thevoltagechangecanbecalculatedtoobtainthedeformationdegreeofthecomponent,soastoachievethepurposeofmonitoringtheconditionofthecomponentandguidetherelevantengineeringpersonneltodealwithit.Thissystemcanbeappliedtothevoltagegeneratedbytheelectricbridge.AschematicdiagramoftheelectricbridgeisshowninFigure9.Inthefigure,R4,R3,R1,andR2arethefourarmsofthebridge,R4andR3arefixedresistancesofimpedance,andR1andR2areinOneisaresistorwhoseresistancevaluechangesafterbeingstressed.R4andR3havethesameresistancevalue,andR1andR2havethesameresistancevaluewhentheyarenotstressed.Inthecaseofnoforce,thetwopointsofthebridge3and4areequipotential,thatis,thepotentialdifferenceis0.IfitisinputasAD620,theinputsignalisconsideredtobe0,andthebridgeissaidtobebalancedatthistime.WhentheforceofR1orR2changes,theresultofthechangeisreflectedinitsresistancevalue,whichcanbeobtainedbyOhmslaw.Thepotentialatpoints3and4isdifferent,thatis,thereisapotentialdifference.Atthistime,thebridgeisoutofbalance,butatthistimeThesignalisveryweakandcannotbecollecteddirectly.Therefore,thesignalisamplifiedthroughthesignalconditioningcircuitmentionedinthearticle,thatis,points3and4inthebridgeareconnectedtopins2and3ofAD620,afteramplification,thenA/Dacquisitionisperformed.Figure9SchematicdiagramofelectricbridgeThissystemusesasimpleelectricbridgebuiltbyitselfduringsimulation,asshowninFigure10.Figure10SimpleelectricbridgeByadjustingR2inthefigure,differentweaksignalsaregenerated,andthesimplebridge1and2areconnectedtothesignalconditioningcircuit,andthenafterA/Dconversion,weaksignalacquisitioncanberealized.The1,2endsofthesimpleelectricbridgecorrespondtothe3and4endsinthefigure.Inthissimulation,adjustR2togenerateabout5.35mVatbothendsof1,2andadjusttheexternalresistanceinthesignalconditioningcircuitto160.7.Thecalculatedmagnificationisabout308.4times,andtheA/Dreferencevoltageis4.256VBymeasuringtheoutputofAD620,itcanbeobtainedthatthevoltageis1.645V,andthemagnificationfactorG=1.647V/5.35mV308canbecalculated.Itcanbeseenthatthemagnificationeffectisgood(afterremovingthemagnificationeffect,theerrorisonlynVlevel).ThroughmultipleA/Dconversions,thereturnedresultsareallaround0x018B,whichprovesthatthesystemhashighcredibility(ithasbeenusedinactualsystems).VI.ConclusionThisarticledescribesindetailthedesignandimplementationofsmallsignalacquisitionsystemsfromchipselection,circuitdesign,etc.,suchas8-bitsingle-chipSTC12C5A60S2asthecontrollerandA/Dconverter;AD620asthemainchipofthesignalconditioningcircuit;electricbridgeprincipleetc.Throughthetest,thecircuithasrealizeditsfunctionwell,andithasaccomplishedtheexpectedgoalexcellentlyintheactualsystem,whichhascertainpracticalvalue.FAQWhatisAD620?AD620isalow-cost,high-precisioninstrumentationamplifier.Itonlyrequiresanexternalresistortosetthegain.Thegainrangeis1to10,000.CanIchangeAD620toAD623whenmakingMCUproducts?BothAD620andAD623aresingleinstrumentationamplifiers,andthepinarrangementisexactlythesame.Themaindifferenceis:AD620mustusepositiveandnegativepowersupplies,AD623canbeapositiveandnegativepowersupplyorasinglepowersupply.IftheoriginalboardisAD620,youcanreplaceitwith623;iftheoriginalboardisAD623,youmaynotbeabletoreplaceitwith620(itdependsonwhetherthepowersupplyoftheoriginalboardcircuitisdualpowersupplyorsinglepowersupply).AfterreplacingAD620andAD623insingle-chipproducts,theprogramcanworknormallywithoutmodification.WhatisthedifferencebetweenAD620BRandAD620AN?Theirpackagesaredifferent.WhatistheoutputresistanceofAD620?Howtoadjustit?AD620isakindoflowpowerconsumptioninstrumentamplifier,itsoutputresistanceisabout10K,thisistheinherentcharacteristicofthischip,generallyitisdifficulttoadjust.Ifyouhaverequirementsforoutputresistance,youcangenerallyuseanexternalcircuittosolveit.IsAD620apositivephaseamplificationorareversephaseamplification?AD620isaninstrumentamplifier,theoutputvoltageis[(Vin+)-(Vin-)]*gain.Ifthedesiredsignalis(Vin+)-(Vin-),thegainispositive,whichisequivalenttopositiveamplification.Conversely,ifthedesiredsignalis(Vin-)-(Vin+),thegainisequivalenttonegative,whichisequivalenttoreverseamplification.Whatisaninstrumentationamplifier?Instrumentationamplifier,animprovementofthedifferentialamplifier,hasaninputbuffer,doesnotrequireinputimpedancematching,sothattheamplifierissuitableformeasurementandelectronicinstruments

DescriptionThe2N7000isaN-ChannelEnhancementModeFieldEffectTransistor,a.k.a.MOSFETforvoltagecontrolledsmallsignalswitching.2N7000NChannelEnhancementModeMOSFETSwitchCircuitBasicsCatalogDescription2N7000Pinout2N7000Parameters2N7000Features2N7000Applications2N7000Advantage2N7000SwitchingWaveformsandTestCircuit2N7000PackageInformation2N7000PopularitybyRegion2N7000AlternativesHowtouse2N7000Wheretouse2N7000ProductManufacturerFAQOrdering&Quantity2N7000PinoutPinNumberPinNameDescription1SourceCurrentflowsoutthroughSource2GateControlsthebiasingoftheMOSFET3DrainCurrentflowsinthroughDrain2N7000ParametersConfigurationSINGLEWITHBUILT-INDIODEContinuousDrainCurrent(ID)200mADrainCurrent-Max(ID)0.2ADraintoSourceResistance5RDraintoSourceVoltage(Vdss)60VDrain-sourceOnResistance-Max5DSBreakdownVoltage-Min60VElementConfigurationSingleFeedbackCap-Max(Crss)5pFFETTechnologyMETAL-OXIDESEMICONDUCTORGatetoSourceVoltage(Vgs)30VHeight5.33mmJEDEC-95CodeTO-92JESD-30CodeO-PBCY-T3LeadFreeLeadFreeLength5.21mmManufacturerMicrochipTechnologyIncManufacturerPartNumber2N7000-GP003MaxPowerDissipation1WNumberofChannels1NumberofElements1NumberofTerminals3OperatingModeENHANCEMENTMODEOperatingTemperature-Max150COperatingTemperature-Min-55CPackageTO-92-3PartLifeCycleCodeActivePolarity/ChannelTypeN-CHANNELReachComplianceCodeCompliantREACHSVHCNoSVHCRiskRank5.56SurfaceMountNOTerminalFormTHROUGH-HOLETerminalPositionBOTTOMTransistorApplicationSWITCHINGTransistorElementMaterialSILICONVoltageRating(DC)60VWeight0.00776ozWidth4.19mm2N7000FeaturesFreefromsecondarybreakdownLowpowerdriverequirementEaseofparallelingLowCISSandfastswitchingspeedsExcellentthermalstabilityIntegralsource-draindiodeHighinputimpedanceandhighgain2N7000ApplicationsMotorcontrolsConvertersAmplifiersSwitchesPowersupplycircuitsDrivers(relays,hammers,solenoids,lamps,memories,displays,bipolartransistors,etc.)The2N7000hasbeenreferredtoasaFETlingtonandasanabsolutelyidealhackerpart.ThewordFETlingtonisareferencetotheDarlington-transistor-likesaturationcharacteristic.Atypicaluseofthesetransistorsisasaswitchformoderatevoltagesandcurrents,includingasdriversforsmalllamps,motors,andrelays.Inswitchingcircuits,theseFETscanbeusedmuchlikebipolarjunctiontransistors,buthavesomeadvantages:highinputimpedanceoftheinsulatedgatemeansalmostnogatecurrentisrequiredconsequentlynocurrent-limitingresistorisrequiredinthegateinputMOSFETs,unlikePNjunctiondevices(suchasLEDs)canbeparalleledbecauseresistanceincreaseswithtemperature,althoughthequalityofthisloadbalanceislargelydependentontheinternalchemistryofeachindividualMOSFETinthecircuitThemaindisadvantagesoftheseFETsoverbipolartransistorsinswitchingarethefollowing:susceptibilitytocumulativedamagefromstaticdischargepriortoinstallationcircuitswithexternalgateexposurerequireaprotectiongateresistororotherstaticdischargeprotectionNon-zeroohmicresponsewhendriventosaturation,ascomparedtoaconstantjunctionvoltagedropinabipolarjunctiontransistor2N7000AdvantageTheSupertex2N7000isanenhancement-mode(normallyoff)transistorthatutilizesaverticalDMOSstructureandSupertexswell-provensilicon-gatemanufacturingprocess.Thiscombinationproducesadevicewiththepowerhandlingcapabilitiesofbipolartransistors,andthehighinputimpedanceandpositivetemperaturecoefficientinherentinMOSdevices.CharacteristicofallMOSstructures,thisdeviceisfreefromthermalrunawayandthermally-inducedsecondarybreakdown.SupertexsverticalDMOSFETsareideallysuitedtoawiderangeofswitchingandamplifyingapplicationswhereverylowthresholdvoltage,highbreakdownvoltage,highinputimpedance,lowinputcapacitance,andfastswitchingspeedsaredesired.2N7000SwitchingWaveformsandTestCircuit2N7000PackageInformation3-LeadTO-92PackageOutline(N3)FrontView3-LeadTO-92PackageOutline(N3)SideView3-LeadTO-92PackageOutline(N3)BottomView2N7000PopularitybyRegion2N7000AlternativesManufacturerManufacturerPartNo.LifecycleStatusIndicatorMicrochipSupertex2N7000-GVolumeProductionHowtouse2N7000AMosfethasthreeterminals:Drain,SourceandGate.ThecurrentalwaysentersthroughtheDrainandleavesthroughtheSource.TheGatepinactsasaswitchtoturntheMosfetonoroff.IftheGateisconnectedtoground,theMosfetisswitchedoff,i.e.thereisnoconnectionbetweentheDrainandtheSource(open).IftheGateissuppliedwithitssourcevoltage(VGS)thentheMOSFETwillbeON,i.e.theDrainandSourcepinswillbeconnectedtogether(Closed).Thus,bycontrollingthevoltage(VGS),wecanswitchtheMOSFET,makingtheMOSFETavoltage-controlleddevice.Thegate-sourcevoltage(VGS)isacriticalparameterwhenusingthetransistor.Forthistransistor,theVGSis20V,sowhenwesupplythisvoltage,theMOSFETwillbecompletelyclosed.Anyvaluebetween20VcausestheMOSFETtopartiallyclose,creatingapartialconnection.TheloadswitchedbytheMOSFETcanreach60V(VDS)andcanconsumeupto200mA(ID).GivenbellowisaverysimplecircuitunderneaththatusesthisMOSFETtocontrola24V2Aloadmotor.Thecurrentandvoltagevaluescanalsobeobservedwhentheswitchisclosedandopen.AsweknowthatthevoltageofthegridsourceofthisMosfetis20V,weused20VtoturnontheMOSFET.Whenthegateswitchisopen,theMosfetsgatepinmustbeconnectedtogroundtocuttheload,soweuseda10KresistortoturnofftheMOSFETafterturningiton.TheRGresistorisacurrentlimitingresistorthatlimitstherequiredgridcurrent.IftheloadcontrolledbytheMOSFETisaninductiveloadlikethemotorwehaveusedhere,thenitismandatorytouseaflywheeldiodetosafelydischargetheloadaccumulatedbytheinductivecoil.Wheretouse2N70002N7000isasmallN-channelMOSFET.MOSFETsareelectronicpowerswitches,justliketransistors,butwithahighercurrentandvoltagerating.The2N7000MOSFETcanbeusedtoswitchloadsthatoperateonlessthan60V(VDS)and200mA(ID).ThismosfetcomesinacompactTO-92packageandhasathresholdvoltageof3V,soifyouarelookingforasmallmosfettoswitchaload,thisICmightberightforyou.ProductManufacturerMicrochipTechnologyInc.isaleadingproviderofmicrocontrollerandanalogsemiconductors,providinglow-riskproductdevelopment,lowertotalsystemcostandfastertimetomarketforthousandsofdiversecustomerapplicationsworldwide.HeadquarteredinChandler,Arizona,Microchipoffersoutstandingtechnicalsupportalongwithdependabledeliveryandquality.FAQWhatisa2n7000Mosfet?2N7000isasmallsignalN-channelMOSFET.MOSFETsarepowerelectronicswitchesjustliketransistors,butwithahighercurrentandvoltagerating.The2N7000MOSFETcanbeusedtoswitchloadswhichoperatesonlessthan60V(VDS)and200mA(ID).Whatisamaximumoperatingvoltageforthe2n7002transistor?The2N7002isalogiclevelMOSFETwithalowon-stateresistance.Themosfethasalowgatetosourcethresholdvoltageof2.1Vtypicallythismakesthemosfetsuitableevenfor3.3Vapplicationcircuits.WhatisMosfetgatethresholdvoltage?ThethresholdvoltagerepresentsthevoltageatwhichtheMOSFETstartstoturnon,whilstthemaximumgate-sourcevoltageisthemaximumgate-sourcevoltagethattheMOSFETcanwithstandsafely.WhatisanchannelMosfet?TheN-ChannelMOSFEThasanN-channelregionlocatedinbetweenthesourceanddrainterminals.Itisafour-terminaldevicehavingtheterminalsasgate,drain,source,body.InthistypeofFieldEffectTransistor,thedrainandsourceareheavilydopedn+regionandthesubstrateorbodyareofP-type.DescriptionThe2N7002isalogiclevelMOSFETwithalowon-stateresistance.Themosfethasalowgatetosourcethresholdvoltageof2.1Vtypicallythismakesthemosfetsuitableevenfor3.3Vapplicationcircuits.Sincethemosfethaslowonstateresistanceithashighefficiencyduringwhenthemosfetinon.Duetothispropertyitcanmaintainhighswitchingperformanceandhenceusedwidelyinpowermanagementapplications.ThemosfetalsocomesinaSMDpackagehencecanbeusedforcompactapplications.Oneconsiderabledisadvantageofthemosfetisitslowdraincurrent;itcanprovideacontinuouscurrentof200mAandpeakscurrentsupto1Aatmaximumthresholdvoltage.Anythingmorethanthatwilldamagethemosfet.CatalogDescriptionPinConfigurationFeaturesDucumentsandMediaPackageOutlineApplicationsAlternativesProductManufacturerOrdering&QuantityPinConfigurationPinNo.PinNameDescription1GateControlsthebiasingoftheMOSFET2SourceCurrentflowsoutthroughSource3DrainCurrentflowsinthroughDrainFeaturesSuitableforlogiclevelgatedrivesourcesSurface-mountedpackageVeryfastswitchingTrenchMOSFETtechnologyDocumentsandMediaDatasheet2N7002N-ChannellogiclevelMOSFETDatasheetPackageOutlineApplicationsLowcurrentandLowVoltageswitchingapplicationsDC-DCconverterseMobilityapplicationsApplicationwherelowon-stateresistanceisrequired.PowermanagementapplicationsAlternativesNTR4003,FDC666,FDC5582N7002EquivalentP-Channel:BSS84,FDN358POtherN-ChannelMOSFETs:BS170N,IRF3205,2N7000,IRF1010E,IRF540NProductManufacturerNXPSemiconductorsN.V.(NXP)isaholdingcompany.TheCompanyoperatesasasemiconductorcompany.TheCompanyprovideshighperformancemixedsignalandstandardproductsolutions.TheCompanyssegmentsareHighPerformanceMixedSignal(HPMS),StandardProducts(SP),andCorporateandOther.Itsproductsolutionsareusedinarangeofend-marketapplications,includingautomotive,personalsecurityandidentification,wirelessandwirelineinfrastructure,mobilecommunications,multi-marketindustrial,consumerandcomputing.Itengageswithglobaloriginalequipmentmanufacturers(OEMs)andsellsproductsinallgeographicregions.NXPsHPMSsegmentincludesbusinesslines,suchasAutomotive,SecureIdentificationSolutions(SIS),SecureConnectedDevices(SCD),andSecureInterfacesandInfrastructure(SII).TheCompanysSPsegmentsuppliesarangeofstandardsemiconductorcomponents,suchassmallsignaldiscretesandpowerdiscretes.

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