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Design >> Analog Design >> why my LC-tank start to oscillate from 0V?
https://designers-guide.org/forum/YaBB.pl?num=1157450390

Message started by sugar on Sep 5^th, 2006, 2:59am

Title: why my LC-tank start to oscillate from 0V?
Post by sugar on Sep 5^th, 2006, 2:59am

I have an ideal LC-tank with one node connected to ground, and
then I set another node's initial condition to 1V, but the transicent
waveform starts to oscillate from 0V, why doesn't it start to oscillate from 1V?

by the way, I'm using spectre doing those simulation.

Title: Re: why my LC-tank start to oscillate from 0V?
Post by Ken Kundert on Sep 5^th, 2006, 6:33am

Spectre imposes the initial condition by performing a DC analysis with a 1 V voltage source in series with a 1 Ω resistor attached to the capacitor. But the capacitor is shorted by the inductor, so your attempt to apply an initial condition on the capacitor actually acts to put an initial condition on the inductor. The reverse would be true if you tried to impose an initial condition on the inductor.

-Ken

Title: Re: why my LC-tank start to oscillate from 0V?
Post by sugar on Sep 5^th, 2006, 9:23pm

I see. thank you, Ken.