The first problem that jumps immediately to my eye is your power supply is backwards.
-Chuck Harris Jenny Lee wrote: > Hi Everyone, I was hoping to get some words of wisdom on my oscillator that > only oscillates in simulation! I have a > MEMS device that resonates around 34 MHz at a given bias with Q of 100. I fit > the impedance into a six-element > equivalent model (similar to 4-element equivalent model of Quartz) and placed > in a Colpitts configuration for the > simulation. In the open-loop gain/phase plot, the peak barely passes 0 dB no > matter what C1 and C2 I chose. For > transient simulation, it does oscillates, but on a PCB, the circuit won't > oscillate! I'm including the device > impedance, circuit schematics and simulation results as an attachment. I've > managed to oscillate 20 MHz device which > has a higher maximum impedance than 34 MHz devices both in simulation and on > a PCB - but for this I followed the > guidelines of Colpitts for Quartz ranging at 10~20MHz. But above 20 MHz, for > Quartz, overtones seem to be the way to > go due to the manufacturing so I couldn't find any reference or circuits that > operates Quartz for 30 MHz~50MHz ranges > at a fundamental mode. I can only use fundamental mode for my device... I > would really appreciate if you could share > some of your experiences with Colpitts or any suggestions of what I can try > to make it work... Thank you!-Jenny > _________________________________________________________________ In a rush? > Get real-time answers with Windows Live > Messenger. > http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refresh_realtime_042008 > > > ------------------------------------------------------------------------ > > _______________________________________________ time-nuts mailing list -- > time-nuts@febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the > instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
