使用微控制器的模拟比较器模块制作Δ - Σ转换器

Thisapplicationnotedescribeshowtoimplementan

Analog-to-Digital(A/D)Converterfunctionusinga

memberofthePIC16C6XXseriesofmicrocontrollers.

Althoughthesemicrocontrollersdonothaveabuilt-in

A/DConverterlikeothercontrollersfromMicrochip,the

comparatorfunction,internalvoltagereferenceandtim-

erscanbeusedtodigitizeananalogsignal.

SomeofthestandardPICmicroshaveacomparator

module,consistingoftwocomparators,bothofwhich

canbeconnectedtoPORTAinavarietyofconfigura-

tions.Theinternalvoltagereferencedividercanbe

usedwiththecomparatorstoestablishthresholds.

Additionally,oneofthecomparatorinputscanbecon-

figuredtotheRA2portallowingfortheuseofanexter-

nalvoltagereference.Bycombiningtheseelements,a

firstordermodulatorandfirstorderfiltercanbe

designed,emulatingthefunctionofananalog-to-digital

delta-sigmaconversion.MAN700MakeaDelta-SigmaConverterUsingaMicrocontroller’sAnalogComparatorModuleThismethodofconversionisquicklyimplementedinAuthors:DieterPeterrmwarewithveryfewadditionalexternalcomponents.BonnieC.BakerConsequently,thecostofhardwareimplementationisDanButlerminimal,particularlyforsuchahighresolutioncon-HartonoDarmawaskita