Subject: RE: [IBIS-Users] Temperature Range:
From: Mellitz, Richard (richard.mellitz@intel.com)
Date: Thu Mar 28 2002 - 06:32:20 PST
Al,
Regarding the statement: "High temperature is always low capacitance,
therefore "fast"."
Is only true of buffers whose slew rate is controlled by capacitance. There
are adaptive slew rate and driver strength schemes that can change the
dependence of slew rate and buffer strength on temperature. Just some food
for thought. :-)
Rich Mellitz,
Intel
-----Original Message-----
From: Al Davis [mailto:aldavis@ieee.org]
Sent: Wednesday, March 27, 2002 8:23 PM
To: ibis-users@server.eda.org
Subject: Re: [IBIS-Users] Temperature Range:
On Wednesday 27 March 2002 17:43, Peters, Stephen wrote:
> Actually, IBIS models with a 'min' temperature higher than the
> 'max' temperature are perfectly correct, assuming the part being
> modeled is CMOS. As explained on pg. 57 of the IBIS spec, the 'min'
> value of [Temperature Range] is the value that causes or amplifies
> the slow/weak condition, while the 'max' value is the value that
> causes or amplifies the fastest/strongest condition. With CMOS,
> cold is fast & hot is slow. TTL logic is just the opposite.
That doesn't make sense. The only place it is actually used in
calculations in transit time, when [TTpower] or [TTgnd] keywords are
used. These define the nonlinear capacitance in parallel with the
clamps. High temperature is always low capacitance, therefore "fast".
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