基于斜率比较ADC

Comparatorsareusedformanythings,butmanypeo-

plewanttobuildanalog-to-digitalconvertersusinga

comparator.Comparatorsareonebasicbuildingblock

ofallADCarchitectures.APICmicro

®

microcontroller

withinternalcomparatorscanbecomeanADCwiththe

applicationofsomesoftwareandaminimumofexter-

nalhardware.Inthisapplicationnoteyouwillbeshown

howtobuildaSlopeADC.ThisADChasbeenused

withthedigitalpinsonPICmicromicrocontrollersfor

manyyears.Theadditionofacomparatortothecircuit

improvestheresultsandreducesthepowerconsump-

tion.AN863AComparatorBasedSlopeADCThermistorsAuthor:JosephJulicherThermistorsaredevicesthatchangeinresistancewithMicrochipTechnologyInc.changesintemperature.Thermistorsaremoreprop-erlycalledRTDs(ResistiveTemperatureDetectors).INTRODUCTIONAnRTDcanbemadefromavarietyofsubstancesdependingonthedesiredoper