A4988-数据手册

4988-DSFeaturesandBenefits▪LowRDS(ON)outputs▪Automaticcurrentdecaymodedetection/selection▪MixedandSlowcurrentdecaymodes▪Synchronousrectificationforlowpowerdissipation▪InternalUVLO▪Crossover-currentprotection▪3.3and5Vcompatiblelogicsupply▪Thermalshutdowncircuitry▪Short-to-groundprotection▪Shortedloadprotection▪Fiveselectablestepmodes:full,1/2,1/4,1/8,and1/16Package:DescriptionTheA4988isacompletemicrosteppingmotordriverwithbuilt-intranslatorforeasyoperation.Itisdesignedtooperatebipolarsteppermotorsinfull-,half-,quarter-,eighth-,andsixteenth-stepmodes,withanoutputdrivecapacityofupto35Vand±2A.TheA4988includesafixedoff-timecurrentregulatorwhichhastheabilitytooperateinSloworMixeddecaymodes.ThetranslatoristhekeytotheeasyimplementationoftheA4988.SimplyinputtingonepulseontheSTEPinputdrivesthemotoronemicrostep.Therearenophasesequencetables,highfrequencycontrollines,orcomplexinterfacestoprogram.TheA4988interfaceisanidealfitforapplicationswhereacomplexmicroprocessorisunavailableorisoverburdened.Duringsteppingoperation,thechoppingcontrolintheA4988automaticallyselectsthecurrentdecaymode,SloworMixed.InMixeddecaymode,thedeviceissetinitiallytoafastdecayforaproportionofthefixedoff-time,thentoaslowdecayfortheremainderoftheoff-time.Mixeddecaycurrentcontrolresultsinreducedaudiblemotornoise,increasedstepaccuracy,andreducedpowerdissipation.DMOSMicrosteppingDriverwithTranslatorandOvercurrentProtectionContinuedonthenextpage…A4988MicrocontrollerorControllerLogicVDDVREFGNDGNDRESETENABLESLEEPDIRMS2MS3MS1STEPVBB1CP1VCPVREGVDDROSC5kΩ0.22μF0.22μF0.1μF0.1μF100μFCP2VBB2OUT1AOUT1BSENSE1OUT2AOUT2BSENSE2A4988Approximatesize28-contactQFNwithexposedthermalpad5mm×5mm×0.90mm(ETpackage)TypicalApplicationDiagramDMOSMicrosteppingDriverwithTranslatorandOvercurrentProtectionA49882AllegroMicroSystems,Inc.115NortheastCutoffWorcester,Massachusetts01615-0036U.S.A.1.508.853.5000;(UVLO),andcrossover-currentprotection.Specialpower-onsequencingisnotrequired.TheA4988issuppliedinasurfacemountQFNpackage(ES),5mm×5mm,withanominaloverallpackageheightof0.90mmandanexposedpadforenhancedthermaldissipation.Itislead(Pb)free(suffix–T),with100%mattetinplatedleadframes.Description(continued)AbsoluteMaximumRatingsCharacteristicSymbolNotesRatingUnitsLoadSupplyVoltageVBB35VOutputCurrentIOUT±2ALogicInputVoltageVIN–0.3to5.5VLogicSupplyVoltageVDD–0.3to5.5VVBBxtoOUTx35VSenseVoltageVSENSE0.5VReferenceVoltageVREF5.5VOperatingAmbientTemperatureTARangeS–20to85ºCMaximumJunctionTJ(max)150ºCStorageTemperatureTstg–55to150ºCSelectionGuidePartNumberPackagePackingA4988SETTR-T28-contactQFNwithexposedthermalpad1500piecesper7-in.reelDMOSMicrosteppingDriverwithTranslatorandOvercurrentProtectionA49883AllegroMicroSystems,Inc.115NortheastCutoffWorcester,Massachusetts01615-0036U.S.A.1.508.853.5000;=25°C,VBB=35V(unlessotherwisenoted)CharacteristicsSymbolTestConditionsMin.Typ.2Max.UnitsOutputDriversLoadSupplyVoltageRangeVBBOperating8–35VLogicSupplyVoltageRangeVDDOperating3.0–5.5VOutputOnResistanceRDSONSourceDriver,IOUT=–1.5A–320430mΩSinkDriver,IOUT=1.5A–320430mΩBodyDiodeForwardVoltageVFSourceDiode,IF=–1.5A––1.2VSinkDiode,IF=1.5A––1.2VMotorSupplyCurrentIBBfPWM50kHz––4mAOperating,outputsdisabled––2mALogicSupplyCurrentIDDfPWM50kHz––8mAOutputsoff––5mAControlLogicLogicInputVoltageVIN(1)VDD0.7––VVIN(0)––VDD0.3VLogicInputCurrentIIN(1)VIN=VDD0.7–201.020μAIIN(0)VIN=VDD0.3–201.020μAMicrostepSelectRMS1MS1pin–100–kΩRMS2MS2pin–50–kΩRMS3MS3pin–100–kΩLogicInputHysteresisVHYS(IN)Asa%ofVDD51119%BlankTimetBLANK0.711.3μsFixedOff-TimetOFFOSC=VDDorGND203040μsROSC=25kΩ233037μsReferenceInputVoltageRangeVREF0–4VReferenceInputCurrentIREF–303μACurrentTrip-LevelError3errIVREF=2V,%ITripMAX=38.27%––±15%VREF=2V,%ITripMAX=70.71%––±5%VREF=2V,%ITripMAX=100.00%––±5%CrossoverDeadTimetDT100475800nsProtectionOvercurrentProtectionThresholdIOCPST2.1––AThermalShutdownTemperatureTTSD–165–°CThermalShutdownHysteresisTTSDHYS–15–°CVDDUndervoltageLockoutVDDUVLOVDDrising2.72.82.9VVDDUndervoltageHysteresisVDDUVLOHYS–90–mV1Forinputandoutputcurrentspecifications,negativecurrentisdefinedascomingoutof(sourcing)thespecifieddevicepin.2Typicaldataareforinitialdesignestimationsonly,andassumeoptimummanufacturingandapplicationconditions.Performancemayvaryforindividualunits,withinthespecifiedmaximumandminimumlim