晶体振荡器的基础和晶体rfPICM和PIC微®器件选择

Oscillatorsareanimportantcomponentofradiofre-

quency(RF)anddigitaldevices.Today,productdesign

engineersoftendonotfindthemselvesdesigningoscil-

latorsbecausetheoscillatorcircuitryisprovidedonthe

device.However,thecircuitryisnotcomplete.Selec-

tionofthecrystalandexternalcapacitorshavebeen

lefttotheproductdesignengineer.Iftheincorrectcrys-

talandexternalcapacitorsareselected,itcanleadtoa

productthatdoesnotoperateproperly,failsprema-

turely,orwillnotoperateovertheintendedtemperature

range.Forproductsuccessitisimportantthatthe

designerunderstandhowanoscillatoroperatesin

ordertoselectthecorrectcrystal.AN826CrystalOscillatorBasicsandCrystalSelectionforrfPICTMandPICmicroDevicesWhattemperaturestabilityisneeded?Author:StevenBibleMicrochipTechnologyInc.Whattemperaturerangewillberequired?Whichenclosure(holder)doyoudesire?INTRODUCTIONWhatloadcapacitance(CL)doyourequire?Whatshuntcapacitance(C0)doyourequire?Oscillatorsareanimportantco