实用的PICmicro振荡器的分析与设计

Thereisawealthofinformationwrittenonthesubject

ofdesigningandanalyzingoscillatorcircuits.Sources

rangefromacademicandresearchpaperstoindustry

generatedapplicationguides.Itisadauntingtaskfor

theembeddeddesignertoworkthroughalltheavail-

ableandsometimesconflictinginformation.Allthe

designerisreallyinterestedinisasimplesetofrules

resultinginareliableoscillatordesignthatwillwork

despitecrystalaging,deviationsbetweendevices,

temperatureorvoltage.Theproblemisthesimple

CrystalPierceGateOscillator(Figure1)hasa“simpli-

fied”model(Figure2)thatisanythingbutsimple.None

ofthevaluesarefixed.Somevarywithprocess,age,

temperatureandvoltage.Somecomponentshavea

nonlinearbehaviorwithamplitude.AN943PracticalPICmicroOscillatorAnalysisandDesignThepurposeofthisdocumentistoexplainthemostAuthor:RuanLourenscriticalaspectstodesigningandanalyzingareliableMicrochipTechnologyInc.PICmicroMCUbasedoscillator.Note:ReadingapplicationnotesAN826,CrystalOscillatorBasicsandCrystalSelectionforINTRODUCTIONrfPICandPICmicroDevicesan