TPS63030中文资料(16)

元器件交易网SLVS696–

LAYOUTCONSIDERATIONS

Asforallswitchingpowersupplies,thelayoutisanimportantstepinthedesign,especiallyathighpeakcurrentsandhighswitchingfrequencies.Ifthelayoutisnotcarefullydone,theregulatorcouldshowstabilityproblemsaswellasEMIproblems.Therefore,usewideandshorttracesforthemaincurrentpathandforthepowergroundtracks.Theinputcapacitor,outputcapacitor,eacommongroundnodeforpowergroundandadifferentoneforcontrolgroundtominimizetheeffectsofgroundnoise.ConnectthesegroundnodesatanyplaceclosetooneofthegroundpinsoftheIC.

ThefeedbackdividershouldbeplacedascloseaspossibletothecontrolgroundpinoftheIC.Tolayoutthecontrolground,itisrecommendedtouseshorttracesaswell,separatedfromthepowergroundtraces.Thisavoidsgroundshiftproblems,whichcanoccurduetosuperimpositionofpowergroundcurrentandcontrolgroundcurrent.

THERMALINFORMATION

Implementationofintegratedcircuitsinlow-profileandfine-pitchsurface-mountpackagestypicallyrequiresspecialattentiontopowerdissipation.Manysystem-dependentissuessuchasthermalcoupling,airflow,addedheatsinksandconvectionsurfaces,andthepresenceofotherheat-generatingcomponentsaffectthepower-dissipationlimitsofagivencomponent.

Threebasicapproachesforenhancingthermalperformancearelistedbelow. ImprovingthepowerdissipationcapabilityofthePCBdesign

ImprovingthethermalcouplingofthecomponenttothePCBbysolderingthePowerPAD Introducingairflowinthesystem

FormoredetailsonhowtousethethermalparametersinthedissipationratingstablepleasechecktheThermalCharacteristicsApplicationNote(SZZA017)andtheICPackageThermalMetricsApplicationNote(SPRA953)