RTD温度传感器的振荡器电路

Thisapplicationnoteshowshowtodesigna

temperaturesensoroscillatorcircuitusingMicrochip’s

low-costMCP6001operationalamplifier(opamp)and

theMCP6541comparator.Oscillatorcircuitscanbe

usedtoprovideanaccuratetemperaturemeasurement

withaResistiveTemperatureDetector(RTD)sensor.

Oscillatorsprovideafrequencyoutputthatispropor-

tionaltotemperatureandareeasilyintegratedintoa

microcontrollersystem.

RCoscillatorsofferseveraladvantagesinprecision

sensingapplications.Oscillatorsdonotrequirean

Analog-to-DigitalConverter(ADC).Theaccuracyofthe

frequencymeasurementisdirectlyrelatedtothequality

ofthemicrocontroller’sclocksignalandhigh-frequency

oscillatorsareavailablewithaccuraciesofbetterthan

10ppm.AN895OscillatorCircuitsForRTDTemperatureSensorsAuthor:EzanaHaileandJimLepkowskiRTDsserveasthestandardforprecisiontemperatureMicrochipTechnologyInc.measurementsbecauseoftheirexcellentrepeatabilityandstabilitycharacteristics.ARTDcanbecharacter-izedoverit’stemperaturemeasurementrangetoINTRODUCTIONobtainatableofcoefficientsthatcanbeaddedtothe