具有可编程增益放大器的温度传感

Althoughitissimpletomeasuretemperatureina

stand-alonesystemwithoutthehelpofMicrochip’sPro-

grammableGainAmplifiers(PGA),avarietyofprob-

lemscanbeeliminatedbyimplementingtemperature-

sensingcapabilityinmultiplexedapplicationswitha

PGA.Oneofthemainadvantagesisthatyoucanelim-

inateasecondsignalpathtothemicrocontrollerand

stillmaintaintheaccuracyofyoursensingsystem.In

particular,themultiplexedPGAsyoucanusearethe

MCP6S22(two-channel),MCP6S26(six-channel),and

MCP6S28(eight-channel).

Themostcommonsensorsfortemperaturemeasure-

mentsaretheThermistor,SiliconTemperatureSensor,

RTDandThermocouple.Microchip’sPGAsarebest

suitedtointerfacetotheThermistororSilicon

TemperatureSensor.

Inthisapplicationnotewewilldiscusstheimplementa-

tionoftemperaturemeasurementsystemsfromsensor

tothePICmicro

®

microcontrollerusingaNTCTher-

mistor,SiliconTemperaturesensor,PGA,anti-aliasing

filter,A/Dconverterandmicrocontroller.MAN867TemperatureSensingWithAProgrammableGainAmplifierAuthor:BonnieC.BakerMicrochipTechnologyInc.10000000NTCThermistorResistance()10k@25Cthermistor1000000INTRODUCTION100000Althoughitissimpletomeasuretempera