Re: Ver. 3.2 and Ver. 2.1 Models

Thanks, Scott.

More questions:
It looks like the IBIS Accuracy Handbook simply advises that the user determine
the transmission-line parameters of the standard test board by doing lab-tests
(TDR measurements). I'm curious if anyone has done so and would be willing to
share those numbers. And/or has anyone used a 2D field solver on the board
design file to get the RLGC parameters for the "50 ohm microstrip transmission
line which is 8 inches long".

Thanks.

-- 
Regards,
Stephen M. Nolan
Scott McMorrow wrote:
> 
> Stephen,
> 
> Stephen Nolan wrote:
> >What is "the IBIS Accuracy Trailer"?
> 
> Here is the directory for it on the IBIS website.
> 
> http://www.vhdl.org/pub/ibis/accuracy/
> 
> The Trailer is a bunch of comment lines at the end of
> a model which are intended to document the correlation
> of an IBIS model to actual measurements.  It was developed
> by a number of IBIS users, along with the accuracy spec and
> handbook, because of their frustration with poor model
> quality.
> 
> We use the correlation metric which is defined by the
> specification to compare IBIS simulations with SPICE
> simulations and document these in the models we produce
> with the Accuracy Trailer.
> 
> In our case, the standard test circuit we use is a driver
> driving a 50 ohm microstrip transmission line which
> is 8 inches long into a 5pF capacitive load.  This gives
> us loads of information on the quality of IBIS simulations
> into a fairly complex reflected wave environment.  Typically
> our correlations are within 98 to 99% of the original
> Spice waveform, according to the metric.
> 
> We now deliver all models with correlation data to the
> orignal source.  Additionally, we provide reports with
> pictures of the comparision waveforms to our end customers,
> which are usually semiconductor manufacturers.
> 
> best regards,
> 
> scott
> 
> Scott McMorrow
> Principal Engineer
> SiQual, Signal Quality Engineering
> 18735 SW Boones Ferry Road
> Tualatin, OR  97062-3090
> (503) 885-1231
> http://www.siqual.com