一个使用PIC mcu 的DC / DC转换器控制器

Inmanyapplications,aDC/DCConverterisusedto

producearegulatedvoltageorcurrent,derivedfroman

unregulatedpowersupply,orfromabattery.Examples

oftheseapplicationsincludebatterychargers,elec-

tronicairpurifiers,emergencyexitsigns,anddistrib-

utedpowersystems.

Insomeofthoseapplications,adedicatedSwitched

ModePowerSupply(SMPS)ControllerICisusedin

conjunctionwithamicrocontroller.Inotherapplica-

tions,however,adedicatedSMPSControllerICmaybe

overkill.Analternativeapproachistogeneratealow

costSMPSfunctioninasmartmicrocontroller,suchas

thePIC16C620A.ThisApplicationNoteshowsa

methodofusingthemicrocontrollertoperformsimple

SMPScontrolfunctions.

Twocircuitswerebuiltforevaluation.Onecircuitpro-

videsaConstantVoltageoutput,theotheraConstant

Currentoutput.AN216DC/DCConverterControllerUsingaPICmicroMicrocontrollerInanytypeofDC/DCConvertercircuit,thepowerAuthor:HartonoDarmawaskitadeviceselectionsareveryimportant.Thekeyparame-MicrochipTechnologyInc.terstolookforinthetransistorQ1aretheswitchingtimeandcurrentrating.Thesetwoparametersgreatlyaffectthemaximumswitchingfrequencyofthecon-