I'd like to add a bit to Andy's response, where he says: -----Original Message----- SPICE is known to occasionally have numeric oscillations when it should be steady-state, which can be fixed by changing to Method=Gear. ------------------------== The numeric oscillations that can be cured by METHOD=GEAR are very distinctive: they look like a sawtooth wave in which the timepoints oscillate between two values (this behavior sometimes will damp out over time, but usually will continue between exactly the same two values). The key characteristic is the sawtooth wave pattern with only two timepoints per period. If you have an oscillation that looks like a sawtooth (or just a high frequency ringing) but with more than two timepoints defining one period of the ringing, this won't be helped by changing the integration method. By the way, this sawtooth pattern is called "Trap ringing" because it's a characteristic of the trapezoidal integration method SPICE uses by default. Kim ----------------------------------------------------------------- |For help or to subscribe/unsubscribe, email majordomo@eda.org |with the appropriate command message(s) in the body: | | help | subscribe ibis <optional e-mail address, if different> | subscribe ibis-users <optional e-mail address, if different> | unsubscribe ibis <optional e-mail address, if different> | unsubscribe ibis-users <optional e-mail address, if different> | |or email a request to ibis-request@eda.org. | |IBIS reflector archives exist under: | | http://www.eda.org/pub/ibis/email_archive/ Recent | http://www.eda.org/pub/ibis/users_archive/ Recent | http://www.eda.org/pub/ibis/email/ E-mail since 1993Received on Wed Jan 4 09:11:06 2006
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