On Tuesday 15 December 2009, Lars Snith wrote: > 2.40 -12.7710mA -7.5000mA -21.3261mA > 2.46 -12.8090mA -8.0000mA -21.3770mA > 2.52 -12.8400mA -7.0000mA -21.4280mA > 2.58 -12.9000mA -7.0000mA -21.4810mA > 2.64 -13.0000mA -7.0000mA -21.5310mA > 2.70 -13.0000mA -8.0000mA -21.5800mA > 2.76 -13.0000mA -8.0000mA -21.6300mA > 2.82 -13.0000mA -10.0000mA -22.0000mA > 2.88 -13.0000mA 0.0A -22.0000mA > 2.94 -10.0000mA -10.0000mA -22.0000mA > 3.00 -10.0000mA -10.0000mA -22.0000mA > 3.06 -20.0000mA -10.0000mA -20.0000mA > 3.12 -20.0000mA 0.0A -20.0000mA > 3.18 -10.0000mA -10.0000mA -30.0000mA > 3.24 -10.0000mA -10.0000mA -20.0000mA > 3.30 -10.0000mA -10.0000mA -20.0000mA > 3.36 -10.0000mA -10.0000mA -30.0000mA > 3.42 -20.0000mA 0.0A -20.0000mA > 3.48 -20.0000mA -10.0000mA -20.0000mA > 3.54 -10.0000mA -10.0000mA -30.0000mA > 3.60 -10.0000mA -10.0000mA -20.0000mA It's not toggle. It's numerical noise. It's not just noise buried under the numbers, those numbers are nothing but numerical noise. You get things like this from the subtraction that separates the clamps from the composite. The clamp current in this region is usually huge, and exists only as a figment of the simulator. A real device would let the smoke out and not work any more. You need more precision in currents, and less precision in voltage. It may cause convergence problems seemingly at random. Some have argued that only the sum of the clamps and pullup/down matters, but you can still get glitches that cause trouble. Usually, it doesn't matter because it never operates in this region, where clamp diodes are forward biased. Once in a while, a non-converged iteration will land there and throw the process off, leading to non-convergence, or more likely just a few more iterations. This problem has existed for years. Most dedicated SI simulators will filter out bad data like this, without even a warning. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. -------------------------------------------------------------------- |For help or to subscribe/unsubscribe, e-mail majordomo@eda-stds.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 e-mail a request to ibis-request@eda-stds.org. | |IBIS reflector archives exist under: | | http://www.eda-stds.org/pub/ibis/email_archive/ Recent | http://www.eda-stds.org/pub/ibis/users_archive/ Recent | http://www.eda-stds.org/pub/ibis/email/ E-mail since 1993Received on Tue Dec 15 20:39:46 2009
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