LDO的散热考虑

Battery-operatedequipment(mostnotablycellphones

andnotebookcomputers)havecreatedastrong

demandforlinearregulatorsinsmallpackages.While

suchpackagessavespace,theyalsohavepoorheat

transfercharacteristics.Tominimizepowerdissipation,

theseregulatorsaredesignedtoworkwithverylow

input/outputvoltagedifferentials,hencethename“low

dropoutregulators”orLDOs.

LDOsspecifymaximumoutputcurrentandinput

voltagelimits,butblindlyoperatingtheLDOwithin

theselimitswillsurelyresultinexceedingthemaximum

powerdissipationcapability.MAN761LDOThermalConsiderationsTheconservationofpower,statesthatpowerinmustAuthor:PaulPaglia,equalpowerout.Consequently,inputpowerisequaltoMicrochipTechnologyInc.thepowerdeliveredtotheloadplusthepowerdissipatedintheLDO,(Equation1):INTRODUCTIONEQUATION1:Battery-operatedequipment(mostnotablycellph