高压微控制器的设计

Whendesigningembeddedmicrocontroller

applications,oneofthegreatestchallengescanbethe

creationofthepowersupplyforthemicrocontroller.

Particularlywhentheonlysupplyvoltageavailableis

significantlyhigherthanthemicrocontroller’smaximum

VDD.

Tohelpsimplifyembeddeddesign,Microchiphas

introducedanewfeatureinaselectgroupofnew

microcontrollerofferings,a5Vshuntregulator.This

on-chipregulatorallowsthemicrocontrollertooperate

fromawidevarietyofsupplyvoltages.Asanadded

bonus,theshuntregulatortopologyalsoallowsthe

connectionofothercircuitry,externaltothe

microcontroller,tobepoweredbytheVDDpin.

Thisapplicationnotediscussesthedesignofpower

supplycircuitsusingthenewshuntregulator,and

presentssomeTips‘nTricksforextendingthe

regulator’scapabilities.AN1035DesigningwithHVMicrocontrollersSo,allwereallyneedtoknowtodesignwithashuntAuthor:KeithCurtisregulatorisOhm’sLaw.TheproblemisthatthesupplyMicrochipTechnologyInc.voltage,VUNREG,isnotconstantandneitheristheloadcurrent.Inaddition,therangeofcurrentoverwhichtheregulatorhascontrol,isalsolimited.SothechoiceofINTRODUCTIONRSERreallybecome