让你的振荡器工作

ManyMicrochipcustomersaskusforhelpwhen

designingtheiroscillatorcircuits.Duetothegreatnum-

berofcombinationsofVDDandtemperatureranges,

crystalorresonator,loadingcapacitors,circuitlayout

andcircuitboardmaterials,itisnotpracticaltoprovide

acookbookprocessthatwouldworkwellforeveryone

orevenformostusers.However,therearemeasures

thatcanbeusedtodevelopandtestforgoodworking

oscillatorcircuits.

Thisapplicationnotebreaksdowntheoscillatordesign

processintothefollowingthreeparts:specifyingthe

operatingconditions,selectingthecomponentsand

testingoscillatorperformance.Otherconcernsarealso

discussedthatmaybehelpfulduringlayoutand

testing.AN949MakingYourOscillatorWorkTemperatureAuthor:BrettDuaneTheproductisexpectedtooperateoversometemper-MicrochipTechnologyInc.aturerange.Testingofoscillatoroperationwillbeconductedoverthesameorslightlylargerrange.Thetemperatureaffectstransistorgain,capacitorvaluesINTRODUCTIONandthecrystal/resonatorfrequency.ManyMic