RE: [IBIS-Users] pullup resistor in a receiver

From: Tom Dagostino <tom_at_.....> Date: Thu Mar 03 2005 - 16:21:51 PST · This archive was generated by hypermail 2.1.8 : Thu Mar 03 2005 - 16:24:45 PST

There are a couple of ways of doing this.  The most common is to add the
effect of the pullup resistor to the input model's powerclamp table.
Another method is to add a Series element and use a series resistor to model
the pullup resistor.  You do not want to use a terminator model because a
terminator model does not have Vinl and Vinh, required to do timing
analysis.

With a table model like the powerclamp you can model non-linear resistance.
With a series resistor you can change values very easy, you are changing a
single resistance value.

Tom Dagostino
Teraspeed Labs
13610 SW Harness Lane
Beaverton, OR 97008
503-430-1065
http://www.teraspeed.com
tom@teraspeed.com

Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
401-284-1827

Teraspeed is the registered service mark of
Teraspeed Consulting Group LLC

-----Original Message-----
From: owner-ibis-users@eda.org [mailto:owner-ibis-users@eda.org]On
Behalf Of RODRIGUEZ_LECONA_RAMIRO
Sent: Thursday, March 03, 2005 4:00 PM
To: ibis-users@eda.org; ibis-info@eda.org
Subject: [IBIS-Users] pullup resistor in a receiver

Hi all,

        If I have a receiver with a pullup resistor, What is the correct way
to include the termination effect: add the termination current to the [POWER
Clamp] curve or specify the model_type as “terminator” and add the pullup
resistor in the [Rpower] keyword?

        Thanks in advance

        Regards,

        Ramiro

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