晶振的负性阻抗

OscillatorMatchingTest Date 05 14 2004ApplicationEngineer ArvinChiangE mail arvinchiang tw Agenda Instruments Introductionoscillationcondition Howtoanalyzeanoscillationcircuitonboard Howtomendoptimumoscillationcondition Instruments TektronicTDS620BOscilloscope HP53181ARFCounter ADVANTESTR3754NetworkAnalyzer HP34401ADigitalMultimeter Motech1201SwithPowerSupply TektronicCT 1CurrentTransformerProbe 5mV 1mA TektronicP6249 CL 1pf Probe SWRBridge50ohm Mini CircuitsFTB 1 1 Howtoanalyzeanoscillationcircuitonboard NegativeResistanceDriverLevelFrequency OnboardandX talSingle FundamentalOscillateCircuit FrequencyMeasure TektronicCT 1CurrentProbe 5mV 1mA Measuremode HP53181ACounter circuitprobe DriveLevelMeasure VrmsMeasure Irms Vrms 5 TektronicCurrentProbe 5mV 1mA RL R1 1 C0 CL 2DriveLevel Irms2 RL CircuitProbe Ex R1 25ohm C0 3pf CL 16pfVrms 8mVIrms 8 5 1 6 mA RL 25 1 3 16 2 35 25 ohm DriverLevel 1 62 35 25 90 24 uW SingleFrequencyN R Measure FromnoOscillatetoOscillatebyadjustVR N R 5to10 RLN R VR RLRL R1 1 C0 CL 2 DigitalMultimeter VR VR Circuitprobe AllFrequencyRangN R Measure R3754NETWORK RecommendedOscillationCondition Negativeresistance N R 5to10 RL RL R1 1 Co CL 2Loadcapacitance 10pf 20pf Drivellevelrange 1uW 500uW Typ 100uWFrequencymatchingonboard Howtomendoptimumosc