AN_SY8292_TSR_Vinson

ApplicationNote:AN_SY8292HighEfficiency,800kHz,40VInput,2AAsynchronousStepDownRegulatorAN_SY8292Rev.0.9CSilergyCorp.Confidential-PreparedforCustomerUseOnly1GeneralDescriptionTheSY8292isahighefficiency800kHz,adaptiveconstantOFFtimecontrolledasynchronousstep-downDC-DCregulatorcapableofdelivering2Aoutputcurrent.TheSY8292canoperateoverawideinputvoltagerangefrom5Vto40VandintegratemainswitchwithverylowRds(on)tominimizetheconductionloss.Lowoutputvoltagerippleandsmallexternalinductorandcapacitorsizesareachievedwith800kHzswitchingfrequency.OrderingInformationPackageCodeTemperatureCodeOptionalSpecCode□□□□(□□□□□□□□)□□□□SY8292PackageCodeTemperatureCodeOptionalSpecCode□□□□(□□□□□□□□)□□□□SY8292Features•5-40Vinputvoltagerange•LowRds(on)forinternalN-channelPowerFET:180mΩ•800kHzswitchingfrequency•AdaptiveconstantOFFtimecontrol•Internalsoftstartlimitstheinrushcurrent•2%0.6Vreference•Hic-cupmodeshortcircuitprotection•Cyclebycyclepeakcurrentlimit•Thermalshutdownprotection•RoHSCompliantandHalogenFree•Compactpackage:SOT23-6Applications•SetTopBox•PortableTV•AccessPointRouter•DSLModem•LCDTVTypicalApplicationsLXINGNDFBENBSL6.8uHDCOUT22uFVOUT=5VVINCIN4.7uFOFF/ONCBS100nFR1100kΩR213.7kΩCFF22pFFigure1.SchematicDiagramFigure2.EfficiencyFigureOrderingNumberPackagetypeNoteSY8292ABCSOT23-6--SilergyCorp.Confidential-PreparedforTSRAN_SY8292AN_SY8292Rev.0.9CSilergyCorp.Confidential-PreparedforCustomerUseOnly2Pinout(topview)BSGNDFBLXINEN123654(SOT23-6)TopMark:HDxyz(Devicecode:HD,x=yearcode,y=weekcode,z=lotnumbercode)PinNamePinNumberPinDescriptionBS1Boot-StrapPin.Supplyhighsidegatedriver.DecouplethispintoLXpinwith0.1uFceramiccap.GND2GroundpinFB3OutputFeedbackPin.Connectthispintothecenterpointoftheoutputresistordivider(asshowninFigure1)toprogramtheoutputvoltage:VOUT=0.6*(1+R1/R2)EN4Enablecontrol.Pullhightoturnon.Donotfloat.IN5Inputpin.DecouplethispintoGNDpinwithatleast4.7uFceramiccapLX6Inductorpin.ConnectthispintotheswitchingnodeofinductorBlockDiagramFETDriverPeakCurrentSenseThermalShutdownControlBlockInputUVLOENSilergyCorp.Confidential-PreparedforTSRAN_SY8292AN_SY8292Rev.0.9CSilergyCorp.Confidential-PreparedforCustomerUseOnly3AbsoluteMaximumRatings(Note1)SupplyInputVoltage-----------------------------------------------------------------------------------------------------------42VEnableVoltage-----------------------------------------------------------------------------------------------------------VIN+0.6VFBVoltage-----------------------------------------------------------------------------------------------------------------------3.6VBStoLXVoltage---------------------------------------------------------------------------------------------------------------3.6VPowerDissipation,PD@TA=25°C,SOT23-6--------------------------------------------------------------------------0.6WPackageThermalResistance(Note2)θJA--------------------------------------------------------------------------------------------------------------170°C/WθJC--------------------------------------------------------------------------------------------------------------130°C/WJunctionTemperatureRange------------------------------------------------------------------------------------------------150°CLeadTemperature(Soldering,10sec.)------------------------------------------------------------------------------------260°CStorageTemperatureRange--------------------------------------------------------------------------------------65°Cto150°CRecommendedOperatingConditions(Note3)SupplyInputVoltage--------------------------------------------------------------------------------------------------5Vto40VBStoLXVoltage---------------------------------------------------------------------------------------------------------------3.3VJunctionTemperatureRange--------------------------------------------------------------------------------------40°Cto125°CAmbientTemperatureRange---------------------------------------------------------------------------------------40°Cto85°CSilergyCorp.Confidential-PreparedforTSRAN_SY8292AN_SY8292Rev.0.9CSilergyCorp.Confidential-PreparedforCustomerUseOnly4ElectricalCharacteristics(VIN=12V,VOUT=5V,L=6.8uH,COUT=22uF,TA=25°C,IOUT=1Aunlessotherwisespecified)ParameterSymbolTestConditionsMinTypMaxUnitInputVoltageRangeVIN540VInputUVLOThresholdVUVLORising4.5VInputUVLOThresholdFalling4.3VInputUVLOHysteresisVUVLO_HYS200mVQuiescentCurrentIQIOUT=0,VFB=VREF×105%160µAShutdownCurrentISHDNEN=010µAFeedbackReferenceVoltageVREF0.5880.60.612VFBInputCurrentIFBVFB=VIN-5050nAPowerFETRONRDS(ON)1180mΩPowerFETCurrentLimitILIM2.4AENRisingThresholdVENH1.5VENFallingThresholdVENL0.4VMinimumOFFTimeTOFF100nsMinimumONTimeTOFF100nsMaximumONTimeTON2usOscillatorFrequencyFOSC800kHzSoftstartTimetSS500µsThermalShutdownTemperatureTSD150°CThermalShutdownRecoveryHysteresisTHYS15°CNote1:Stressesbeyondthe“AbsoluteMaximumRatings”maycausepermanentdamagetothedevice.Thesearestressratingsonly.Functionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedintheoperationalsectionsofthespecificationisnotimpl