TRANSONEROverview.PiezoelectrictransformersforCCFLbacklightingFaceElectronics,LC.,Virginia,USADecember5,2001Dr.AlfredoVázquezCarazo427W.35thSt.Norfolk,VAUSAPhone:757.624.2121Fax:757.624.2128alfredo@CharlieElliott,PulseEngineeringPiezoelectricTransformersMagneticTransformerRosen-typePiezo-TransformerTransonerPiezo-TransformerUnitsincmTransformersforCCFLbacklightingPiezoelectricity:BasicconceptsPiezoelectricTransformersINVERSEPIEZOELECTRICEFFECTElectricaltoMechanicalenergyconversionDIRECTPIEZOELECTRICEFFECTMechanicaltoElectricalenergyconversion

PZT:DiscoveredinJapanearlyinthe1950s.Thesematerialsareusableatleastto250o.BackgroundonPiezoelectricTransformersPiezoelectricTransformersTypesof‘Rosen’-piezoelectrictransformersPiezoelectricTransformersFamilyPhotosBackgroundonPiezoelectricTransformers(PTs)Rosen:FirstPatentonPTsBerlincourt:Ballastforgaseousdischargelamp(VermitronCorp.)PTsforTVreceivers–HVforcathoderay.(DenjiOnkyoLimited,Matsushita,Motorola,RCACorp.)PTsfortriggeringpowerswitchesgateswithgalvanicdecoupling(Triacs,Tiristors,Mosfets,etc.):Siemens,GeneralElectric.PTsforbacklightCCFLinlap-topcomputers.(NEC,Murata,Matsushita,Taiheiyo,Tamura,Motorola,Tokin,etc.)195870’s70s80s85stopresentIncreasePowerDensity:SmallersizesCurrenttargetBackgroundonPiezoelectricTransformersPiezoelectricTransformersWhatwaswrongwith“those”Piezo-trafosSUCCESFULLYIMPROVEDSINCE1985’sMaterialDrivingCircuitryManufacturingProcessMountingPZT-Materialunderdevelopment–(1954)(lowQ,highdielectriclosses,lowcouplingcoef.).HighSinteringMaterialsExpensiveNotape-castingtechniquesLimitonsizesDoublePolarizationProcessnooptimizedReliablehousingtechniquesunderdevelopmentElectroniccircuitbasedondiscretecomponentsLimitedPOWERCAPABILITIES(5W/cm3)

PowerHowdotheyoperate?.Resonance010203040506070InputImpedanceopencircuitconditionsImpedance[Ohms]1stlongitudinalmode(fundamental)3rdlongitudinalmode100200300400500600Frequency[kHz]-100-80-60-40-200204060Phase[Degrees]fRfABackgroundonPiezoelectricTransformersPiezoelectricTransformers/2mode3/2modePiezoelectricTransformersFeatures:SimpleconstructionwithoutwindingsNowindingshortsduringoperationNomagneticfieldinvolveintheoperation(reducedRFandEMI)LowprofileHighefficiencyNon-flammable98%TypicalEfficiencyNoHighVoltage“CoronaEffect”PureSineWaveOutput(MinorDistortion)SurfaceTemperatureraisingT35Kduetotheirexcellentthermaldissipationbehavior.Piezoelectricvs.Magnetic

5W

50W

100W

220W

1kV

10V

5kV

10kV

MaterialImprovements

DimensionalRedesign

ModularDesign

PowerDelivery[W]

OutputVoltage[Vp]

Step-upratio?50-100

InputVoltageinCCFLapplicat.

(NEC,Tokin,Murata,etc)

JAPAN(1985-2000)

Improvements

USA1958

Rosen-type

T6T1T3

USA1998

TRANSONERTECHNOLOGY

(FaceInter.Corp)

NewPiezo-TrafotechnologiesPiezoelectricTransformersT3-HVTransonerPiezoelectricTransformersRosenvs.TransonerTRANSONERADVANTAGESSimpleachievementofISOLATIONcapabilities>35kVbyaddingaisolationlayerThestackconceptallowsaLARGERMECHANICALCOUPLINGAREAandthusahigherpowerdensityINPUTANDINPUTCAPACITANCEScanbeindependentlydesignedwithouthavingthesamethickness.Largerstep-upratiosAsaresultSMALLERSIZESandmorecompactandefficientinvertercanbedevelopedRosen-typeTransoner-typeELECTRICALENERGYVoltage,currentELECTRICALENERGYVoltage,currentPPTransducerActuatorTVoutVinFigureofasimpletwo-layerTransonerP=Polarizationdirection T=StressdirectionTransoner:TypesandspecificationsPiezoelectricTransformersPatentNotice:TechnologydisclosedonthispagecoveredbyoneormoreissuedorpendingU.S.andInternationalpatentsownedbyfaceInternationalCorporation,Norfolk,Virginia,USA.T1-TypeTransonerLargePowerStep-upandStep-downMedium,lowimpedanceloads200-1k

(Linearfluorescent)T3-TypeTransonerMedium-lowPower(5-8W)VeryhighStep-up(200)Largeimpedanceloads50k-300k(CCFL)MiniT1TransonerMini-size(5mm2x1mm)Step-upMediumimpedanceloads200-1k

(PDA,CellPhones)Transoner:TypesandspecificationsPiezoelectricTransformersOperationPoint:MaximumEfficiencyApproachtotheOperationPrinciplePiezoelectricTransformersGeneralBehaviorApproachtotheOperationPrinciplePiezoelectricTransformersLoadDependence:CCFLstartingupandContinuousoperationApproachtotheOperationPrinciplePiezoelectricTransformersPiezo-TrafoEquivalentCircuitC=EquivalentStiffnessR=EquivalentMechanicalResistanceL=EquivalentmassPiezoelectricTransformersDrivingCircuitryforPiezoelectricTransformersPiezoelectrictransformerinputsectionsarecharacterizedbyashuntinputcapacitancewhichmayexceedtensofnano-farads.TwowaystodriveaPiezoelectricTransformerSquare-wavesignal:PWMconvertersSine-wavesignal:ResonantconvertersLargeharmoniccontents(Inputdriveharmonicsmayberejectedbythehigh-Qtransformertherebyreducingdriveefficiency.DriveharmonicscanexcitespuriousmodesinthePTwhichwillbedifficulttosuppress.ThecirculatingenergythroughtheshuntinputcapacitanceCd1characteristicoftheinputsectionofPTgeneratedielectriclosses(turn-onlosses).ZeroVoltageSwitchingTechnique:useasquareswitchingsignalwithZVStechniquetominimizeswitchinglosses.DC-ACDrivingCircuitTechniquesPiezoelectricTransformersDrivingCircuitryforPiezoelectricTransformersClass-EDC/A