使用数字电位器来优化精密单电源检测电路

INTRODUCTION

Photodiodesbridgethegapbetweenlightand

electronics.Manytimes,precisionapplications(such

asCTscanners,bloodanalyzers,smokedetectors,

positionsensors,IRpyrometersandchromatographs)

utilizethebasictransimpedanceamplifiercircuitthat

transformslightenergyintoausableelectricalvoltage.

Inthesecircuits,photodiodesareusedtocapturethe

lightenergyandtransformitintoasmallcurrent.This

currentisproportionaltothelevelofilluminationfrom

thelightsource.Apreamplifierthenconvertsthe

current(inamperes)fromthephotodiodesensorintoa

usablevoltagelevel.MAN692UsingaDigitalPotentiometertoOptimizeaPrecisionSingle-SupplyPhotoDetectionCircuitPhotodiodeCharacteristicsAuthor:BonnieC.BakerMicrochipTechnologyInc.AphotodiodecanbeoperatedinthePhotovoltaicorPhotoconductivemode,asshowninFigure2.INTRODUCTIONLightSourcePhotodiodesbridgethegapbetweenlightandLighte