TI隔离技术与产品概览

TIInformation–SelectiveDisclosureTIInformation–SelectiveDisclosureCircuitIsolationTechniques&[e-mail]3Q20131TIInformation–SelectiveDisclosureAgendaTechnicalReviewMarketsandApplicationsCompetitiveAdvantagesProductPortfolioQ&ATIInformation–SelectiveDisclosureTECHNICALREVIEWTIInformation–SelectiveDisclosureTemperatureTheRealWorldPressurePositionSpeedFlowHumiditySoundLightISOLATIONPLCmCDSPDIGITALINTELLIGENCEADCTRANSCEIVERSRS-485/CANSignalIsolationTIInformation–SelectiveDisclosureWhyisIsolationUsed?Isolation-isameansofpreventingcurrentfromflowingbetweentwocommunicatingpoints.-isusedintwogeneralsituations.1)wherethereisthepotentialforcurrentsurgesthatmaydamageequipmentorharmhumans2)whereinterconnectionsinvolvelargegroundpotentialdifferences(GPDs)anddisruptivegroundloopsaretobeavoided.Inbothcasesisolationisusedtopreventcurrentflow,yetallowsfordataorpowerflowbetweenthetwopoints.TIInformation–SelectiveDisclosureDifferentIsolationTechniques•GalvanicIsolation–Isolatedcircuitsexchangesignalswithoutcurrentflow.•TransformerIsolation–AformofGalvanicisolation,configurabletoprovidefrequencyselectiveisolation.–EX:CommonModechokesandBaluns.•JunctionIsolation–Typicallyfoundinlowvoltageapplications.–Highestbreakdownprocessesavailablecanreach1200v(InternationalRectifier).•AmplifierIsolation–InstrumentationAmplifiersandDifferentialAmplifierscomprisethisarea.–HighlevelsofCommonModesignalrejection(isolation)whilemaintainingoramplifyingthesignalsofinterest.–Frequencydependencycanbeaweakness.•WirelessTechnology––Primarilyfocusedonpowertransmission,“TheHolyGrail”ofpowerelectronics.–DielectricthicknessisvariableandFrequencydependenciesmustbespecifiedperapplication.TIInformation–SelectiveDisclosureWhatisIsolation?Galvanicisolation:–AlthoughCircuit1andCircuit2exchangesignals,nocurrent(electrons)passfromCircuit1toCircuit2.Whyisisolationrequiredinelectricalsystems?BreakgroundloopsReducecommonmodenoiseSafetyfromhighvoltagesCircuit1Circuit2SignalsVoltagesupply1Voltagesupply2Ground1Ground2TIInformation–SelectiveDisclosure1)ElectricalInstallationcancauselargeGPDs(groundpotentialdifference)betweentworemotenodes.2)Adirectgroundconnectionbetweenthenodesclosesthegroundloop.3)Noisesources(i.e.electricmotors)inducinglargecurrentsintothegroundmodulatethegroundloopcurrent.4)Thisgroundnoisethenappearsinthesignalpath.1)Anisolatorbreaksthegroundloop,thusremovingsignalpathnoise.2)TheGPDyetstillexistsandtheisolatormustberobustenoughtowithstandthelargevoltagedifferences.GroundLoopSignal&ReturnPathGPDSignal&ReturnPathGPDISOLATORNoIsolationWithIsolationIsolationBenefitsTIInformation–SelectiveDisclosureWhyIsolate??-OtherreasonsISO7241AOPA333ISOADS125524-BitDataTMP101TMS320F2810DSPwithCANControllerCANSensorFanDSPAmpLVC2G06DSP120ΩMotor480VSN75477ISOCANISOAmpAmpISOISO7220MISO7221CISO7221CSN65HVD233ISOISO721120ΩSN65HVD233GrouploopisolationBlockHighVoltageNoiseisolation120VTIInformation–SelectiveDisclosureSignalsreferencedtoGND2CMTI–Thechangeinground1relativeground2.MeasuredinkV/μSec.DataIsolation:Common-ModeTransientEventTIInformation–SelectiveDisclosureKeymethodsofIsolationEwaldGeorgvonKleistinventedthefirstrecordedcapacitor1745MichaelFaradaydemonstratedthetransformerprinciplein1831ZarlinkInventedtheopto-coupler(1968)Others…Sound,RF,light,Mechanical,etcTIInformation–SelectiveDisclosureIsolationTechniques•Allisolatedcouplersarecapacitivecoupled(activeorparasitic)•CIOforanytypeiscomparableCapacitiveISO72XInductiveADuM1xxGMRIL7xOpticalHCPL-07xxCIO1pF1pF1.1pF0.6pFIsolationDielectricSiO2PolyimidePolyimideMoldcompoundCapacitiveOpticalGMRInductiveSource:TIAppnoteSLLA198(Clickonabovelinkforwebinfo)TIInformation–SelectiveDisclosure“BurrBrownAnnouncesIndustry-FirstIsolatedDigitalCouplerUsingCapacitiveBarrierTechnology.”Articlefrom:BusinessWireDated:August19,1998TechnicalInnovationbyTIwithregardtocapacitiveisolationtechnologyimprovementsisimpressive!!CoplanarCapacitorTechnologySomeHistoryTIInformation–SelectiveDisclosureTransmit-ChipReceiver-ChipHV-CapTopplate=AlBottomPlate=SiliconSubstrate(doped)InterLevelDielectric(TonsofSiO2)MoldcompoundBondwireMin14mmHighVoltageCapacitorDetailCrossSectionalViewIsolationVoltageTransmitchipReceivechipHowaretheyconstructed?TIInformation–SelectiveDisclosureInternalConstructionISO72x:IntegratedatprocesslevelOptical:IsolationfunctionalityaddedatpackagelevelADuM1100:IntegratedatprocesslevelTIInformation–SelectiveDisclosureOSCPWMVREFLPFVREFDCLOUTINIsolationBarrierLow–FrequencyChannel(DC...100kbps)High–FrequencyChannel(100kbps...200Mbps)TheLFchannelassurescorrectoutputsignalpolarityduringlossofinputsignal(i.e.wire-break)HFandLFchannelsusedifferentialsignalingforhighnoiseimmunityInthenewarchitecture,allsignaltransitionsgothroughtheHigh-FrequencyChannel.Howdotheywork?TIInformation–SelectiveDisclosureLLHHLHLHSHLLSLHLCDCDS=storepreviousconditionVREFIN’CDABCDBA1.InitialStaging2.RCDifferentiatorStage3.ComparatorStage4.FlipFlopStageCLOCKTRANSFER(DutyCycle=50:50)A(IN’)BC