标签: tc1220

MicrochipTechnologyInc.’sTC1219(switchingfrequencyat12kHz)andTC1220(switchingfrequencyat35kHz)areinvertingchargepumpvoltageconvert-ersthatarespecifiedusingratherlargecapacitors(10µFfortheTC1219and3.3µFfortheTC1220).Thesecapacitorsizesallowthedesignertheluxuryofareasonablylowoutputresistance(25Ωtypical)capableofdrivingloadcurrentsupto25mA.However,theselarger-valueexternalcapacitorsaremoreexpensiveandrequireadditionalprintedcircuitboard(PCB)spacethantheirsmaller-valuedcounterparts.Additionally,thetimerequiredtoshutdownthesechargepumpconvert-ersbecomeslongerwithlarger-valueexternalcapaci-torsandincertainhigher-speedapplications,thisunfortunatefeaturecanbedevastating.AN813ApplyingtheTC1219/TC1220InvertingChargePumpswithSmallExternalCapacitorValuesAuthor:PatrickMarescaConnecttoVINforMicrochipTechnologyInc.+5VDCMeasurements2ConnecttoExternal6VINFunc.Gen.ForTuning……