Subject: question on SPICE to IBIS translation

From: Binshen Meng <[email-masked]>
Date: Thu, 24 Feb 2000 11:31:16 -0800

I have a question on generating V-T curves from SPICE models. How should I
determine the slew rate that is used for the pulse stimulus in the transient
simulation in HSPICE ( tr and tf in the statement: PULSE v1  v2  td  tr  tf
pw  per )?  I have seen many sample simulations using difference slew rates
(or transient rising or falling edges). Do component manufacturers provide
this information in their data sheets? If not, what is the rule of thumb in
determining it? Should that be generally very fast?....

Thanks for your help

Binshen Meng
Pluris, Inc
408-861-4132

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From: [email-masked]
Date: Thu, 24 Feb 2000 14:30:57 -0600

Binshen Meng,

You should use rise and fall times that are consistent with the on-chip
rise and fall times that the driver sees at its input.  These numbers will
depend on the silicon technology, the circuit driving the driver's input,
and the loading (metal and gates) on this circuit.  The manufacturer will
not provide this information on a datasheet.  You could call them up if you
were really serious.

What I would do is see how sensitive your driver is to input rise and fall
time.  Vary the input between 100 ps and 500 ps and see if you notice
anything more than a phase shift in your driver's output waveform.  Try two
or three different loads, including a system-like load.  If things look
pretty much the same, then you're probably safe using any number in this
range

Greg Edlund
Advisory Engineer, Critical Net Analysis
IBM
3650 Hwy. 52 N, Dept. HDC
Rochester, MN 55901
[email-masked]

Binshen Meng <[email-masked]> on 02/24/2000 01:31:16 PM

To:   "[email-masked]'" <[email-masked]>
cc:
Subject:  question on SPICE to IBIS translation

determine the slew rate that is used for the pulse stimulus in the
transient

Thanks for your help

Binshen Meng
Pluris, Inc
408-861-4132