Subject: min typ & max

From: Matt Callicoat <[email-masked]>
Date: Thu, 23 Mar 2000 10:46:03 -0600

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:

Organized by process,

-----------  -SLOW- -TYP-- -FAST-
C_comp        max    typ    min
Temperature   min    typ    max
Voltage       min    typ    max
IV Curves     min    typ    max
VT Curves     min    typ    max

Organized by numerical comparison,

-----------  SMALL   TYP   LARGE
C_comp        min    typ    max
Temperature   max    typ    min
Voltage       min    typ    max
IV Curves     min    typ    max
VT Curves     min    typ    max

Neither way of looking at the organization of the data into min, typ and
max seems to be consistent.  What exactly are the rules governing the
assignment of min, typ and max?

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From: Kellee Crisafulli <[email-masked]>
Date: Thu, 23 Mar 2000 09:47:57 -0800

Hi Matt,

>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

---------------------------------------------------------
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:[email-masked]>
web:    <http://www.hyperlynx.com>
---------------------------------------------------------

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From: "Weston Beal" <[email-masked]>
Date: Thu, 23 Mar 2000 10:59:34 -0800

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:[email-masked]]
Sent: Thursday, March 23, 2000 9:48 AM
To: Matt Callicoat; [email-masked]
Subject: Re: min typ & max, explained (I hope)

Hi Matt,

best wishes..
Kellee