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CurrentSense
ThermalSense
UndervoltageLockout
tps2061,tps2062,tps2063
tps2065,tps2066,tps2067
SLVS490B–DECEMBER2003–REVISEDDECEMBER2004
detaileddescription(持续)
asensefetmonitorsthecurrentsuppliedtotheload.thesensefetmeasurescurrentmoreefficientlythan
conventionalresistancemethods.whenanoverloadorshortcircuitisencountered,thecurrent-sensecircuitry
sendsacontrolsignaltothedriver.thedriverinturnreducesthegatevoltageanddrivesthepowerfetintoits
saturationregion,whichswitchestheoutputintoaconstant-currentmodeandholdsthecurrentconstantwhile
varyingthevoltageontheload.
TheTPS206ximplementsathermalsensingtomonitortheoperatingtemperatureofthepowerdistribution
转变.inanovercurrentorshort-circuitconditionthejunctiontemperaturerises.whenthedietemperaturerises
toapproximately140
°
cduetoovercurrentconditions,theinternalthermalsensecircuitryturnsofftheswitch,
thuspreventingthedevicefromdamage.hysteresisisbuiltintothethermalsense,andafterthedevicehas
cooledapproximately10degrees,theswitchturnsbackon.theswitchcontinuestocycleoffandonuntilthe
faultisremoved.theopen-drainfalsereportingoutput(ocx)isasserted(activelow)whenanovertemperature
shutdownorovercurrentoccurs.
avoltagesensecircuitmonitorstheinputvoltage.whentheinputvoltageisbelowapproximately2v,acontrol
signalturnsoffthepowerswitch.
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