PICmicro®单片机Microchip的MCP3201的模拟 - 数字转换器接口

Manyoftheembeddedcontrolsystemsdesignedtoday

requiresomeflavorofaAnalog-to-Digital(A/D)Con-

verter.Embeddedsystemapplicationssuchasdata

acquisition,sensormonitoringandinstrumentationand

ControlallhavevaryingA/DConverterrequirements.

Forthemostpart,theseA/DConverterrequirements

areacombinationofperformance,cost,packagesize,

andavailability.Microchipoffersavarietyofsolutionsto

meetthesedesignrequirements.Thefirstpossible

solutionistoimplementthePICmicro

®

microcontroller

(MCU).ThePICmicroMCUoffersmanyoptionsfor

smartsolutions.OneofthesefeaturesistheA/DCon-

vertermodule.TheseA/DConvertermodulesarepri-

marilysuccessiveapproximationregister(SAR)type

andrangeinfunctionalityfrom8-to12-bitwithchannel

sizerangesof4to16.Forexample,thePIC16C77has

8-channelsof8-bitA/DConverter,whilethe

PIC17C766has16-channelsof10-bitA/DConverter.

Theseon-boardA/DConvertermodulesfitwellinto

embeddedapplications,whichrequiresa10-35ksps

A/DConverter.

Forthoseapplicationswhichrequireahigherperfor-

manceorremotesensecapability,theMicrochip

MCP3201,12-bitA/DConverterfitsverynicely.AN719InterfacingMicrochip’sMCP3201Analog-to-DigitalConvertertothePICmicroMicrocontrollerTheMCP3201employsaclassicSARarchitecture.Author:RichardL.FischerThedeviceusesaninternalsampleandholdcapacitorMicrochipTechnologyInc.tostoretheanaloginputwhiletheconversionistakingplace.Conversionratesof100kspsarepossibleontheINTRODUCTIONMCP3201.Minimumclockspeed(10kHzor625sps,