低功耗设计指南

Low-powerapplicationsrepresentasignificantportion

ofthefuturemarketforembeddedsystems.Every

year,moredesignersarerequiredtomakedesigns

portable,wirelessandenergyefficient.Thisdocument

seekstosimplifythetransitiontolow-powerapplica-

tionsbyprovidingasinglelocationforthefoundations

oflow-powerdesignforembeddedsystems.The

examplesdiscussedinthisdocumentwillfocuson

powerconsumptionfromtheviewpointofthemicrocon-

troller(MCU).Asthebrainoftheapplication,theMCU

typicallyconsumesthemostpowerandhasthemost

controloverthesystempowerconsumption.

Aswithalldesigns,itisimportantforthedesignerofa

low-powerembeddedsystemtoconsidertrade-offs

betweenpowerconsumption,andotherfactors,suchas

cost,sizeandcomplexity.Whilesomelow-powertech-

niquescanbeusedwithnocosttothesystem,others

mayrequiretrade-offs.Thisguidewillgiveexamplesof

thesetrade-offswhereapplicable.However,itisnot

feasibletodiscussallpossibletrade-offs,soanembed-

deddesignershouldkeepinmindthepossiblesystem

levelimpactsofpower-savingtechniques.

ThisdesignguidewillrefertoLow-Powermodes

availableonPIC

®

MCUs,butwillnotgointodetail

aboutthesefeatures.Forinformationaboutthe

Low-PowermodesavailableonPICMCUdevices,

refertoAN1267,“nanoWattandnanoWattXLP™

Technologies:AnIntroductiontoMicrochip’s

Low-PowerDevices”(DS01267).AN1416Low-PowerDesignGuideAuthors:BrantIveyMainSourcesofPowerConsumptionMicrochipTechnologyInc.InCMOSdevices,suchasmicrocontrollers,thetotalpowerconsumptioncanbebrokendownintotwobroadINTRODUCTIONcategories:dynamicpowerandstaticpower.DynamicpoweristhepowerconsumedwhenthemicrocontrollerLow-powerapplicationsrepresentasignificantportionisrunningandperformingitsprogrammed