LED恒流驱动控制IC QX9910 (英文资料）.docx

SwitchingTypeLEDDriverQX9910GeneralDescriptionQX9910isahighlyefficient,stableandreliablehigh-brightnessLEDlightscontrolledconstantcurrentdriverIC,built-inhigh-precisioncomparators,off-timecontrolcircuit,thecurrentdriveandothercircuits,especiallyforhigh-power,highbrightnessLEDlightmorethanstringconstantcurrentdriver.QX9910fixedoff-timecontrolmode,theoperatingfrequencyupto2.5MHz,allowstheexternalinductorandfiltercapacitor,thevolumedecreaseefficiency,off-timeminimumtime,throughanexternalresistorandcapacitorset,theoperatingfrequencycanbechangedaccordingtouserrequirements.PWMsignalattheEN-endedandcanadjustthebrightnessofLEDlights.Byadjustingtheexternalresistance,highbrightnessLEDlampcancontrolthedrivecurrenttoachievethedesiredLEDbrightnessconstantbrightness,highbrightnessLEDlightstreamingfromafewmilliampsofcurrentto1Ampchange.FeaturesProgrammableLEDdrivecurrentprogrammedrangeofafewmilliampsto1amp.Highefficiency:betterthan90%Wideinputvoltagerange：2.5V400VHighfrequencyAdjustableoperatingfrequency:10KHz-2.5MHzStrongLEDlightfunctiondrive:LEDlightstringfromonetohundredsofhighbrightnessLEDlampsPWMadjustablebrightness：ByEN-side,adjusttheLEDbrightnessApplications220VACpowersupplyLEDlights;RGBLEDlightsbigscreen;220VACpower1.EDlamp;LEDbacklightingflatpaneldisplays;LEDtrafficwarninglights;Constantcurrentchargercontrol;Universalconstantcurrentsource.PinrssT78TOvssT78VDDEN2S0P8-TTOFFEN2MSOP8TT0FFNC巨QX9910S6CSNC3"QX9910M6CSG<Di"TDRVGDTdrPinarrangementPinNo.PinNameDescription1VSSGround2ENChipEnable3NCNoconnection4GNDVbltagefeedback5DRVDriver6CSCurrentsensing7TOFFOfftimeselection8VDDPowersply(2V6.5V)MaximumratedparametervaluesTyPeSymbolDescnptionVahIeUnitVoltageVmaxMaximumvoltageon*DDpins8VVnmviuaxVoltagerangeonEN.CSandFBPinS-0.3-VDD+03VThermalTmIn-maxOperationteneraturerange-20-85TstorageStoragetemperaturerange-40-165ESDVESDESDvoltageforhumanbodymodel2000VElectricalCharacteristicsParameterSymbolTestConditionMinTyPMaxUnitPowersupplyVDD2.56.5VCSpinfeedbackvoltageVcs240250260mVOperationcurrentIDD0.51mAOfftime(WithoUtROFFandCOFF)Toffo620nsStandbycurrentEDDQ1uAENpiuhighlevelvoltageVENH2.0VENpiulowlevelvoltageVENL0.8VDR'RisingTimeTwSE5OOpFcaponDRVPln50nsDR'FaUingTimeTfLL5OOpFcaponDRVpin50nsTypicalApplicationCircuitMainApplicationCityExchange220VpowersupplyLEDlightingapplicationsGreatmeritofhighbrightnessLEDlamps,thecaseforthesamebrightness,savingapproximately80%morethanincandescent,widelyACpowerlightingapplications,agreatalternativetoboththepowergradually,fever,shortlifeincandescenttrend.QX9910particularlysuitablefor110V220VACpowerforlighting,typicalapplicationshowninFigure1,220VACrectifiedthroughtherectifierbridge,willreceiveabout310VDCvoltage.AsQX9910VDDpowersupplyis5.1V,sothrougharesistorandaregulatortotheICpowersupply.IntheMOSFETcontrolvoltageishigh,MOSFETpowerswitchturnson,inductorLstoresenergywhenthecontrolvoltageislow,MOSFEToff,inductorreleasesenergythroughtheSchottkydiodecircuittolightupLEDlightsstring.Circuitparameters:1.LEDaveragecurrentInFigure1,workingincontinuousmode,LEDcurrentIL,theaverageshowninFigure2.IlmaxisLEDlampbythemaximumcurrent.2.DeterminetheoperatingfrequencyFrequencybytheTOFFpinconnectedtotheROSCandCOSCset,ROSCreceivedaVDDterminal,ROSCresistancethesmallerthehigherthefrequency,COSClarger,lowerfrequency.Theleveloftheoperatingfrequencyisdeterminedbasedonactualusage.Thehigheroperatingfrequency,theinductorcanbesmaller,thelowerthecostoftheinductor.1.EDlight-drivendutycycleD=Vout/Vin.FortheMOSFET,on-timeTON,TOFFofftimefortheMOSFET,(restingstage).Telogeniscalculatedasfollows:Toff Roff + 100K (Coff + 10 pF)IfpinisnotconnectedresistorsandcapacitorsTOFFis:Toff=0.51100KQT0pF=5107s1I-DCircuitoperatingfrequencyiscalculatedasfollows:尸=TToffIfTOFFfeetto1OOOPcapacitance,TOFF=51ms,D=0.1,Fisthecircuitoperatingfrequencyisabout20KHz.3 .ChoiceofinductorLInductanceLoftheselectionprincipleistoensurethatflowthroughtheinductorcurrentchangeismuchlessthanthemaximumcurrentthroughtheinductorvalue.Innormaloperation,theinductorisinastateofchargeanddischarge,whentheinputvoltageandoutputvoltageofthepressureishigh,increasethevalueoftheinductor,whenthepressure-hour,youcanuseasmallerinductor.Inordertoreducefluctuationsincurrentflowingthroughtheinductor,thecircuitshouldoperateincontinuousmode.Incontinuousmode,ILminimum.Intherestingstage,flowthroughtheLEDlightsILcalculatedasfollows:aVOUT_1.AlL=TFF1.InordertoflowthroughtheLEDlampcurrentfluctuationislessthanILinductancerVOUTTshouldsatisfy:LToff7zGeneralvaluetomorethanafewhundredmicro-HangHangcents,dependingontheapplicationmaybe.4 .RCSdeterminedresistanceRCSresistanceofdifferent,youcansetthedrivecurrentthroughtheLED,RCSsmaller,theoutputcurrentincreases.RCSselectionformulaisasfollows:n250/PRcs=+0.5ILLEDlightsthroughtheaveragecurrent;general,fluctuationsincurrentILshouldbelessthanone-tenthofIL.5 .TheselectionofMOSFETInthecaseof220VACpowersupply,thefirstMOSFETtoconsiderthepressure,thepressurehigherthanthegeneralrequirementsMOSFET600V.Secondly,accordingtothesizeofthelampcurrentLEDdriver,selecttheIDSMOSFETthemaximumcurrent.Undernormalcircumstances,shouldusetheIDSMOSFETthemaximumcurrentistheLEDlampdrivecurrentofmorethan5times.InadditiontheinternalresistanceofMOSFETissmaller;RDSshouldbelessthan0.5inEuropethefollowing,RDSsmaller,lossintheMOSFETtubepowersmaller,thehighertheefficiencyofthecircuitchanges.6 .LEDbrightnessadjustmentIncreaseintheENsidePWMdimmingsignal,PWMsignalgeneratedbytheCPU,butalsobytheotherpulsesignalgenerator,PWMdutycyclegreaterbrightnessbrighter.LEDbrightnesscontrolusingPWM,veryconvenientandflexible,isthemostcommondimmingmethod,PWMfrequencyfromHztotensofthousandsofKHz.7 .ENenabledterminalTerminationinEN(low)tothetime,QX9910dormantatthistime,theoperatingcurrentislessthanIOuA,sincethepowerconsumptionisverysmall,whentheENterminalishigh,QX9910inworkingcondition,thenno-loadoperatingcurrentapproximately200uA.EN-sidePWMsignaldimmingsignalacceptabletocompletethedimmingfunction.