Subject: Re: R_Pad?

From: [email-masked] (Dileep Divekar)
Date: Tue, 29 Oct 1996 14:11:36 +0800

Arpad Muranyi, Intel Corporation wrote:
 
> I have seen many SPICE models that ignore the resistive properties of the ESD 
> diodes, yielding such large currents at 1 Volt of over or undershoot.  So much 
> for the accuracy of the SPICE models... 
> 

Please do not get confused between the model EQUATIONS and model PARAMETERS.
SPICE diode model equations have the provision for specifying the parasitic
resistance. Of course, if it is not specified in the model PARAMETERS,
it can produce large currents. IBIS models will exhibit similar unrealistic
behavior if the parasitic resistance is not taken into account while
making the ibis model from simulations. It is always possible to use a very
good model improperly to produce unrealistic results. SPICE is not to be
blamed for that.

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Dileep Divekar
Applied Simulation Technology, Inc.
2188 Bering Drive
San Jose, CA 95131

Phone - (408)-434-0967 x 100
Fax   - (408)-434-1003
Email - [email-masked]
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