question about VCO simulation in Cadence - RF Cafe Forums

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yzs
Post subject: question about VCO simulation in Cadence
Unread postPosted: Tue Mar 15, 2005 1:23 pm

i just simulate a very basic LC cross-coupled VCO in Cadence.
trans analysis.

It's weird to me that the results is subjective to simulation time.
say when simulate 20ns, I can see the oscillation wave, while if i change to 10ns or 30ns, the wave is gone and seems not oscillate at all.

And, the Oscillation start time point is varies with the simulation time as well.

Why is that? Is this related to simulation time step?

simulator used is specture. 0.18 RFCMOS

thanks for reply

Posted 11/12/2012