可编程增益放大器的感应灯

Photosensorsbridgethegapbetweenlightandelec-

tronics.Microchip’sProgrammableGainAmplifiers

(PGAs)arenotwellsuitedforprecisionapplications

(suchasCTscanners),buttheycanbeeffectivelyused

inpositionphotosensingapplicationsminusthehead-

achesofamplifierstability.Whenthetwo,sixoreight-

channelPGAisusedinthissystem,theotherchannels

canbeusedforothersensorsoranarrayofphotosen-

sorswithoutanincreaseinsignalconditioninghardware

orPICmicro

®

microcontrollerI/Opinconsumption.The

multiplexerandhigh-speedconversionresponseofthe

PGA/Analog-to-Digital(A/D)conversionallowsthe

photosensorinputsignaltobesampledandquicklyMAN865SensingLightwithaProgrammableGainAmplifierconvertedtothedigitaldomain.Switchingfromchan-Author:BonnieC.Bakernel-to-channelistheneasierwiththeSerialPeripheralMicrochipTechnologyInc.Interface(SPI)fromthePICmicromicrocontrollertothePGA.INTRODUCTION