标签: mcp1612

ThischaptercontainsgeneralinformationthatwillbeusefultoknowbeforeusingtheMCP1612EvaluationBoard.Itemsdiscussedinthischapterinclude:•AboutThisGuide•RecommendedReading•TheMicrochipWebSite•CustomerSupportMCP1612EvaluationBoardUser’sGuide2005MicrochipTechnologyInc.DS51529ANotethefollowingdetailsofthecodeprotectionfeatureonMicrochipdevices:MicrochipproductsmeetthespecificationcontainedintheirparticularMicrochipDataSheet.Microchipbelievesthatitsfamilyofproductsisoneofthemostsecurefamiliesofitskindonthemarkettoday,whenusedintheintendedmannerandundernormalconditions.Therearedishonestandpossiblyillegalmethodsusedtobreachthecodeprotectionfeature.Allofthesemethods,toourknowledge,requireusingtheMicrochipproductsinamanneroutsidetheoperatingspecificationscontainedinMicrochip’sDataShee……

Thedensityofportableelectronicequipmentrequiresthedesignengineertopayparticularattentiontoanumberofimportantdesignparameters.Forthepowerconversioncircuitry,twooftheseparametersaretheefficiencyandthetotalcircuitryfootprint.Keepingtheefficiencyhighextendsbatterylifeandcontrolsthetemperatureriseoftheequipment.LimitingthecircuitryfootprinthelpsminimizethesizeofthePrintedCircuitBoard(PCB)and,ultimately,thetotalcostofthedevice.TheMCP1612isanidealchoiceforsuchadesign.SinceboththeswitchingandsynchronousMOSFETsareinternalandswitchingis1.4MHz,theinductor,inputandoutputcapacitorsizeisminimized.Theoutputvoltageissetbyusingasimpleresistordivider,withahigh-bandwidthloopbeingaccomplishedbyaseriesresistorcapacitortoground.Efficienciesof90%andatypicalshutdowncurrentof0.01µAhelptoextendbatterylife.ThisApplicationNotecontainsalloftheinformationneededtodesignasynchronousbuckconverterusingtheMCP1612.Italsocontainsareal-worlddesignexamplewithmeasuredlaboratorydata.AN968SimpleSynchronousBuckConverterDesign-MCP1612Author:CliffEllisonSolvingthestandardinductorequationforinductorMicrochipTechnologyInc.ripplecurrent(IL)yields:VLIL=------×TLINTRODUCTION……