单晶体管 46dB 通过减少 LDO 噪音

单晶体管46dB通过减少LDO噪音Maxim>AppNotes>AMPLIFIERANDCOMPARATORCIRCUITSPOWER-SUPPLYCIRCUITSKeywords:Low-dropoutregulator,LDO,RCfilterNov23,2005APPLICATIONNOTE3656SingleTransistorReducesLDONoiseby46dBAbstract:AsimpleRCfilterwithanexternaltransistordriverrejectsLDOnoise.Aplotofnoisedensityvs.frequencyshowsthatthefilterrejectsLDOnoisebymorethan46dB,andachievesanoisefloorof7nV/.Ofthemanylow-dropout(LDO)regulatorsprovidingvoltageregulationforelectronicsystems,somearespecificallydesignedforlownoise.ThevoltageregulatorinFigure1,forexample,achievesanRMSnoisevoltageofabout115V.Someultra-low-noiseapplicationssuchasinstrumentationandhigh-qualit