RE: min typ & max, explained (I hope)

Matt and Kellee,

typ, min, and max refer to the manufacturing tolerance as Kellee stated
except in the case of temperature. Since temperature has opposite effects
in CMOS and TTL, we can not just specify the min and max temperature. The
min temperature is the temperature at which the min IV (and VT) curves are
measured. The same applies to max temperature with max curves. This is
stated in the IBIS specification, I believe. All the other parameters are
specified by numerical min and max.

Regards,
Weston

-----Original Message-----
From: Kellee Crisafulli [mailto:kellee@hyperlynx.com]
Sent: Thursday, March 23, 2000 9:48 AM
To: Matt Callicoat; ibis-users@eda.org
Subject: Re: min typ & max, explained (I hope)

Hi Matt,

At 10:46 AM 3/23/00 -0600, Matt Callicoat wrote:
>I'm a little confused about the definitions of min, typ, and max in the
>ibis specifications. In some cases, it seems to simply mean the
>smallest, middle, and greatest numerical values, respectively. But in
>other cases it seems to refer to slow, typical, and fast, respectively.
>For a CMOS circuit, I believe the convention is as follows:

Min typ and max are used consistently in IBIS as refering to the
parameter they describe. For example: C_comp min,typ,max are the
min,typ,max manufacturing tolerance values that describe C_comp.

For the purposes of choosing a SLOW or FAST process the choice of
which min's and max's to use together is not specified by IBIS. It is
the responsibility of the user together with the simulator to select
the choice of combinations that would say describe the slowest or fastest
output edge rate.

There have been a few discussions in the past about specifying which
combinations are to be used for some of the corners but we could not
agree about how many corners there should be or what parameters they
should be. We ultimately decided to leave this to the simulators and
end users.

best wishes..
Kellee

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Have a great day....
Kellee Crisafulli
HyperLynx, a division of Pads Software Inc.
SI,EMC,X-talk and IBIS tools for the Windows platform
E-mail: <mailto:kellee@hyperlynx.com>
web:   <http://www.hyperlynx.com>
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Received on Thu Mar 23 10:58:17 2000