Andrew, You've posed a good question. I think it cannot be answered in general, but only for a specific part. The IBIS [model] structure may well be adequate in such situations, regardless of large changes in VCC. The historical evidence is that IBIS provides a good model, despite repeated concerns over the years that there are problems just around the corner. Of course, IBIS cannot do everything, but the question in a specific case can only be answered by measurements. Christopher E. Reid Chief Scientist and Founder Pressando SI 9315 SW Lake Street Tigard, OR 97223-6034 503-869-6703 (cell) 503-624-8159 (home) ----- Original Message ----- From: "Andrew Ingraham" <a.ingraham@ieee.org> To: <ibis-users@server.eda.org> Sent: Wednesday, April 19, 2006 5:21 AM Subject: Re: [IBIS-Users] Sweep voltage listing query > What would happen with a model of an IC with a very wide voltage range, > say > for Vcc from 1.0 V to 3.6 V or more? > > For such a part, it may be better to create separate IBIS models for the > different intended ranges; such as, one model for 1.5 V nominal, another > for > 2.5 V, another for 3.3 V, etc. But if you had a single model that worked > well for the entire range (though it is debatable if you could make an > accurate IBIS model to do this), what should it use for its sweep range? > Probably not a Vcc in the middle of the range. > > Are devices tending to have greater relative Vcc voltage ranges? Many 5 V > parts were +/- 5% only. Today's lower voltage parts have wider relative > Vcc > ranges. Perhaps IBIS needs to pay closer attention. > > Just a thought.... > > Andy > > > |------------------------------------------------------------------ > |For help or to subscribe/unsubscribe, email majordomo@eda.org > |with just 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 written 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 1993 > |------------------------------------------------------------------ |For help or to subscribe/unsubscribe, email majordomo@eda.org |with just 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 written 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 Apr 19 09:09:42 2006
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