Subject: Re: Package Parasitics

From: Syed Huq <[email-masked]>
Date: Tue, 24 Apr 2001 15:03:55 -0700 (PDT)

One reason could be is that a ASIC vendor is simply creating "buffer only"
models without any package parasitics. Once the ASIC is defined(with package)
then you create the full IBIS model with all the individual buffers along
with the package parameters..

For a commercially available component, it does not make sense to have
a model without the package parasitics.

Syed
Cisco Systems, Inc 

>
> > |
> > 
> > I have found other models that have these values set to zero:
> > 
> > 
> > > > > [Package]
> > > > > R_pkg   0   0   0
> > > > > L_pkg   0   0   0
> > > > > C_pkg   0   0   0
> > 
> > Can you explain why these values are used, i.e. why the model would be
> > realistic with no package parasitics?
> > 
> > Thanks for your help.
> > 
> > Best regards,
> > Jay Azurin
> > Motorola NetComm Applications
>

---

From: Mark Bossard <[email-masked]>
Date: Wed, 25 Apr 2001 09:10:28 -0400

I agree with Syed... 

The ASIC house I work in does supply ibis models to our customers that
are simply an ibis model for one I/O buffer.  They are many times left
without package RLC so they can be filled in depending on the package
that is used.  

-Mark Bossard
Atmel Chesapeake Design Center

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