桥接遥感和MCP6S2X PGA

ResistivesensorsconfiguredasWheatstonebridges

areprimarilyusedtosensepressure,temperatureor

loads.AnexternalA/Dconverter(ADC)andadigitally

ProgrammableGainAmplifier(PGA)caneasilybeused

toconvertthedifferencevoltagefromtheseresistor

bridgesensorstousabledigitalwordsformanipulation

bythemicrocontroller.WhenthePGAisusedinthis

system,theotherchannelsoftheMCP6S2Xcanbe

usedforothersensorswithoutanincreaseinsignal

conditioninghardwareorPICmicro

®

microcontrollerI/O

pinconsumption.Themultiplexerandhigh-speedcon-

versionresponseofthePGA/Analog-to-Digital(A/D)

conversionallowsadifferentialinputsignaltobesam-

pledandconvertedintheanalogdomainandthen

subtractedinthedigitaldomainwiththemicrocontroller.MAN251BridgeSensingwiththeMCP6S2XPGAsAuthor:BonnieC.BakerBRIDGEDATAACQUISITIONMicrochipTechnologyInc.SYSTEMAnapplicationcircuitforthistypeofsensorenvironmentINTRODUCTIONisshowninFigure1.ResistivesensorsconfiguredasWheatstonebridgesInthiscircuit,thebridgeisexcitedbyavoltagesourceareprimarilyusedtosensepressure,temperatureor(VSEN).Thisreference