L298N中文资料(7)

L298

Figure7:Forhighercurrents,outputscanbeparalleled.Takecaretoparallelchannel1withchannel4

andchannel2withchannel3.

APPLICATIONINFORMATION(Refertotheblockdiagram)1.1.POWEROUTPUTSTAGEEachinputmustbeconnectedtothesourceofthe

drivingsignalsbymeansofaveryshortpath.TheL298integratestwopoweroutputstages(A;B).

ThepoweroutputstageisabridgeconfigurationTurn-OnandTurn-Off:BeforetoTurn-ONtheSup-anditsoutputscandriveaninductiveloadincom-plyVoltageandbeforetoTurnitOFF,theEnablein-monordifferenzialmode,dependingonthestateofputmustbedriventotheLowstate.theinputs.Thecurrentthatflowsthroughtheload

3.APPLICATIONScomesoutfromthebridgeatthesenseoutput:an

Fig6showsabidirectionalDCmotorcontrolSche-externalresistor(RSA;RSB.)allowstodetectthein-maticDiagramforwhichonlyonebridgeisneeded.tensityofthiscurrent.

TheexternalbridgeofdiodesD1toD4ismadeby

1.2.INPUTSTAGEfourfastrecoveryelements(trr ≤200nsec)thatEachbridgeisdrivenbymeansoffourgatesthein-mustbechosenofaVFaslowaspossibleatthe

putofwhichareIn1;In2;EnAandIn3;In4;EnB.worstcaseoftheloadcurrent.TheIninputssetthebridgestatewhenTheEninputThesenseoutputvoltagecanbeusedtocontroltheishigh;alowstateoftheEninputinhibitsthebridge.currentamplitudebychoppingtheinputs,ortopro-AlltheinputsareTTLcompatible.videovercurrentprotectionbyswitchinglowtheen-ableinput.2.SUGGESTIONS

Thebrakefunction(Fastmotorstop)requiresthatAnoninductivecapacitor,usuallyof100nF,must

theAbsoluteMaximumRatingof2AmpsmustbeforeseenbetweenbothVsandVss,toground,

neverbeovercome.asnearaspossibletoGNDpin.Whenthelargeca-pacitorofthepowersupplyistoofarfromtheIC,aWhentherepetitivepeakcurrentneededfromthe

secondsmalleronemustbeforeseenneartheloadishigherthan2Amps,aparalleledconfigura-L298.tioncanbechosen(SeeFig.7).Thesenseresistor,notofawirewoundtype,mustAnexternalbridgeofdiodesarerequiredwhenin-begroundednearthenegativepoleofVsthatmustductiveloadsaredrivenandwhentheinputsofthebeneartheGNDpinoftheI.C.ICarechopped;Shottkydiodeswouldbepreferred.

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