TC620TC621Solid-State温度传感器的应用电路

TheTC620/TC621aresolid-statetemperaturesensors

thatareeasytoprogramandinterfacewithcontrol

equipment.TheTC620sensesthetemperatureinter-

nally,whiletheTC621usesanexternalthermistor.

Figure1showshowthedevicesareconnected.

TheTC620/TC621datasheet(DS21439)describes

howtocalculatethecorrectresistancevalueforany

desiredtemperature.Italsogivesagraphicaldepiction

oftheoutputsforvaryingtemperatures.

SincetheTC620sensestemperaturesinternally,its

outputsmustbelimitedto1mA.Thedevicecansource

orsinkhighercurrents,butinternalself-heatingmay

causeerrorsinthetemperaturesensing.TheTC621

cansourceorsink10mA,sinceitusesanexternalMAN773ApplicationCircuitsoftheTC620/TC621Solid-StateTemperatureSensorsthermistortosensearemotetemperature.InternalAuthor:MicrochipTechnologyInc.heatingwillnotaffectthetemperaturesensingaccuracy.INTRODUCTIONFigure2isaschematicofaheatingandcoolingcon-TheTC620/TC621aresolid-statetemperaturesensorstrollerusingasingleTC620andaTC4469Quadt