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