RE: [IBIS-Users] Minimum #points in Rising/Falling waveform to allow convergence

Hello, Tess,

The IBIS Quality Checklist recommends at least 10 points in a transition
region (for both I-V and V-t tables).
http://www.sisoft.com/ibis-quality/checklist

There are both products and freeware tools that extract more points in the
region of rapid change and fewer points in the flat regions. My favorite
freeware tool is IBISCenter (available under
http://www.eda.org/pub/ibis/training/IBIS_class_2003.zip, use with National
Instruments free LabView Player). If you are a Cadence customer, you could
use "Model Integrity".

Best regards,
Lynne

"IBIS training when you need it, where you need it."

Dr. Lynne Green
Green Streak Programs
http://www.greenstreakprograms.com
425-788-0412
lgreen22@mindspring.com

-----Original Message-----
From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org] On Behalf
Of Tess Trethewey
Sent: Tuesday, September 21, 2004 8:39 AM
To: ibis-users@eda.org
Subject: [IBIS-Users] Minimum #points in Rising/Falling waveform to allow
convergence

Hello IBISers

We discovered that some of our models caused non-convergence in simulation
due to insufficient points in transition region of the rising/falling
waveforms. For example, our V-t curves' timescale was such that we only had
2-3 points in the transition region, with the rest in the 'boring' flat
region after the signal is stable. This caused inconvergence issues in
Spectraquest crosstalk simulations.

We are now revisiting our models to regenerate those that will run into this
problem. However, I don't have a feel for what the 'minimal' number of
points in the transition region is, and I don't want to force regeneration
of models that don't need it.

Does anyone have a feel for the minimum number of points in the transition
region in order to allow convergence?

Thanks for your input
Tess Trethewey
Cypress Applications Engineering

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Received on Tue Sep 21 11:16:58 2004