标签: tc620

TheTC620/TC621aresolid-statetemperaturesensorsthatareeasytoprogramandinterfacewithcontrolequipment.TheTC620sensesthetemperatureinter-nally,whiletheTC621usesanexternalthermistor.Figure1showshowthedevicesareconnected.TheTC620/TC621datasheet(DS21439)describeshowtocalculatethecorrectresistancevalueforanydesiredtemperature.Italsogivesagraphicaldepictionoftheoutputsforvaryingtemperatures.SincetheTC620sensestemperaturesinternally,itsoutputsmustbelimitedto1mA.Thedevicecansourceorsinkhighercurrents,butinternalself-heatingmaycauseerrorsinthetemperaturesensing.TheTC621cansourceorsink10mA,sinceitusesanexternalMAN773ApplicationCircuitsoftheTC620/TC621Solid-StateTemperatureSensorsthermistortosensearemotetemperature.InternalAuthor:MicrochipTechnologyInc.heatingwillnotaffectthetemperaturesensingaccuracy.INTRODUCTIONFigure2isaschematicofaheatingandcoolingcon-TheTC620/TC621aresolid-statetemperaturesensorstrollerusingasingleTC620andaTC4469Quadt……