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,