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