驱动高电流功率型MOSFET开关模式稳压器

Thelowon-resistanceandhighcurrentcarryingcapabilityofpower

MOSFETsmakethempreferredswitchingdevicesinSMPSpower

supplydesign.However,designingwiththesedevicesisnotas

straightforwardaswiththeirbipolarcounterparts.

Unlikebipolartransistors,powerMOSFETshaveaconsiderable

gatecapacitancethatmustbechargedbeyondthethreshold

voltage,V

GS(TH)

,toachieveturn-on.Thegatedrivermustprovide

ahighenoughoutputcurrenttochargetheequivalentgatecapaci-

tance,C

EI

,withinthetimerequiredbythesystemdesign.AN786DrivingPowerMOSFETsinHigh-Current,SwitchModeRegulatorsAuthor:AbidHussain,QGMicrochipTechnology,Inc.QGSQGDQODDRIVINGTHEMOSFETVGS,Gate-to-SourceThelowon-resistanceandhighcurrentcarryingcapabilityofpower