L298N中文资料(7)
发布时间:2021-06-07
发布时间:2021-06-07
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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