RE: Simulation resolution weirdness

Mark,

this often happens when the I-V curves don't have enough data points. If
the slope of the lines connecting the points changes too much, it is hard
for the simulator to follow. It is a kind of numerical noise similar to
what happens in SPICE. If you really need a fine time resolution, you might
ask the vendor for a model with finer detail, or you might add a few points
into the tables to smooth out the corners.

Regards,
Weston

 + -----Original Message-----
 + From: mark.browne@nokia.com [mailto:mark.browne@nokia.com]
 + Sent: Tuesday, September 19, 2000 2:26 AM
 + To: ibis-users@eda.org
 + Subject: Simulation resolution weirdness
 +
 +
 + Hi all,
 +
 + I am fairly new to using IBIS, so I am hoping that the
 + symptoms that I am
 + getting will strike a chord with someone out there.
 +
 + I have run the same simulation several times, changing only the time
 + resolution each time. When the resolution is set to 20ps,
 + the results look
 + fine. However, at 15ps the resultant waveform is just an increasing
 + oscillation, and at 10ps it look like a range of mountains.
 +
 + Obviously I am misusing the method somehow - all I need is
 + for someone to
 + tell me how.
 +
 + Any ideas?
 +
 + Mark Browne
 + Senior Engineer
 + Nokia UK Ltd.
 +

 
Received on Tue Sep 19 09:14:47 2000