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Oscillator Noise Start

Question asked by RANDY_RHEA on Nov 28, 2007
Latest reply on Dec 19, 2007 by SERGEYTRU
Question 1.
The attached file simulates oscillator startup in Cayenne. With the voltage source set at 9 volts, at t=0+ the supply step injects a voltage into the system which rings the resonator. Cayenne parameters are set to start all voltages at 0.
The VCVS provides gain to amplify the supply transient and the signal builds until non-linear action in the VCVS limits the output at about 1 volt. This is expected oscillator starting behavior.
Now, set the supply at 0 volts and rerun the transient analysis. Signal buildup is observed at t>170nS. Since there is no excitation in the circuit, what causes starting?

Question 2.
I would like to simulate starting excited by broadband noise. Apparently I can't use the VNoise model because the documentation states it is active only in linear simulation. The INP_PNoise didn't seem to work. I presume it is active only in Spectrasys. Any suggestions on how to proceed?

Oops! I got an Agilent Access Forbidden message when I attempted to add the WSX file, even though I was logged in. I will send NOISE START.WSX to