RE: R_fixture and R_ref

Paul,

Although R_ref and R_fixture get put in the same topology in respect to the
driver, the use of these to parameters is very different, so I would hope
that no simulator assumes one from the other. R_ref is for board level
timing adjustment while R_fixture partially defines the environment in which
the rising and falling waveforms were measured. I good simulator could
scale the time waveforms if the resistance of the simulation environment is
different than the measurement environment.

Regards,
Weston

-----Original Message-----
From: Paul Gregory [mailto:pgregory@hpbs2933.boi.hp.com]
Sent: Thursday, January 21, 1999 1:14 PM
To: ibis-users@eda.org
Subject: R_fixture and R_ref

In an IBIS model, if R_ref is not specified, is R_fixture used
as a default value? I know that this may be tool specific, but
I hope that there is a common answer.

Of course, the common answer may be to *always* specify R_ref.
Received on Thu Jan 21 11:35:19 1999