基于SG3525两相BUCK电路的设计.pdf

摘

不

功工SG3525为BUCK成

SG3525工及1114

出位180控2控出

1114出510动A3120

动mos动

出工

关：SG3525;PWM,

Abstract

Atpresent,thetransitionfromunilateralpowersupplytomultilateralpowersuppliesisa

bigprogressforpowerconsumptionequipment.Itmakesureofnormaloperationunder

high-powercondition.Thisarticledescribesaswitchingpowersupplycircuitwhichismadeof

theSG3525asthecoreandtwoBUCKcircuitsasthemaincircuit.Inaddition,itintroduces

howtheSG3525chipworksandhowtocontrolthepush-pulloutputthroughthe11pinand

the14pin.Whatthedifferencebetweentwopinsis180degrees,tocontrolthebilateralvoltage

andthedutycycleofoutputpowerisamethodofcontrollingtheeffectonloadvoltage.When

theoutputcurrentofthe11pinand14pinreaches5~10mA,theA3120OCwillbedrove,and

afterthatthemostubegatewillbedrove.Sothenitwilldrivethemaincircuitto

work.Afterward,itwilladjustthevoltagebymeansofcomparingthesamplingvoltageand

correctingthedutycycle.Ifanerroroccurredinonebranchofbilateralpowersupplies,the

otherwouldcontinuetowork.Thatwillensurethesystemtoworknormallyandimprovethe

reliabilityofpowersupply.

Keywords:SG3525;PWM,switchingpowersupply

-I-

录

中文摘I

1引1

1.1及1

1.2-1-

1.31

2件介3

2.1SG3525功及3

2.2PWM控4

36

3.1功6

3.26

3.3DC