Subject: RE: IBIS model for high speed differential application
From: Chris Brewster (chris@siqual.com)
Date: Wed Feb 20 2002 - 11:55:06 PST
Fabrizio,
Yes,
The LVDS IBIS model was extracted from transistor level spice models. The
spice model performs as expected. The IBIS model run in SigXP performs
within 99.6% of the original spice model run in HSPICE.... However, take
the IBIS model, and run it in HSPICE, and the results are no where near
what you would expect....
-Chris
At 05:44 PM 2/19/2002 -0500, zanella, fabrizio wrote:
>Chris, Adam, Perry. Have you requested spice models from the vendors of the
>LVPECL and LVDS devices to run a comparison? All our simulations at
>2.5-3.125Gbs are performed using spice models in Hspice and they work out
>well.
>Regards,
>
>Fabrizio Zanella
>Signal Integrity
>EMC Corporation
>508-249-4645
>fzanella@emc.com
>
>
>
>-----Original Message-----
>From: Adam.Tambone@fairchildsemi.com
>[mailto:Adam.Tambone@fairchildsemi.com]
>Sent: Tuesday, February 19, 2002 3:23 PM
>To: Chris Brewster
>Cc: IBIS group
>Subject: Re: IBIS model for high speed differential application
>
>
>
>I too have experienced difficulties in simulating LVDS IBIS models in
>HSPICE at high frequencies. I wish I had something more constructive to
>add other than to corroborate what has already been said.
>
>Adam Tambone
>
>
>
>
>
>Chris Brewster <chris@siqual.com>@eda.org on 02/19/2002 03:06:36 PM
>
>Sent by: owner-ibis-users@eda.org
>
>
>To: "Perry Qu" <perry.qu@alcatel.com>
>cc: IBIS group <ibis-users@eda.org>
>
>Subject: Re: IBIS model for high speed differential application
>
>
>Perry,
>
>Yes! I have done some LVDS simulations using IBIS at 2.5 and 3.125Gpbs. I
>get very good results with LVDS driver and receiver models, using Cadence
>SigXP. However, when I use the same LVDS IBIS models in HSPICE my results
>go off the chart???
>
>In fact, the driver model in HSPICE gives good results. It's when the
>receiver model is added that things go wacky...
>
>My two cents...
>
>-Chris Brewster
>
>At 12:55 PM 2/19/2002 -0500, Perry Qu wrote:
> >Hi!
> >
> >I have been doing some simulation in HSPICE using IBIS model for a while
> >and encountered many problems, especially when dealing with high speed
> >differential application such as LVPECL, LVDS, etc. The model behave
> >strangely in HSPICE, giving me wierd noise, unbalanced voltage swing,
> >etc. Does this happen to you ? In some cases, the model works ok in
> >other SI simulation tool, such as XTK.
> >
> >In general, what's your comments about using IBIS model for gb/s
> >application ?
> >
> >Thanks in advance for your feedback.
> >
> >Regards
> >
> >PErry
> >
> >--
> >Perry Qu
> >
> >Product Integrity | 600 March Road
> >Alcatel Canada | Ottawa, ON K2K 2E6, Canada
> >
> >DID: (613) 7846720 | FAX: (613) 5993642
>
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