Re: Proposed Golden IBIS Parser checks

Hi IBIS,

At 01:00 PM 11/4/98 -0700, you wrote:
>> >> 3) For non-ECL models, shouldn't the zero current voltage for the
Typ, Min,
>> >> and Max columns in the Pullup or Pulldown V/I tables be the same (say
>> >> within a microvolt)? I suggest that a warning be generated if
they are
>> >> not.
>> >Lots of technologies have zero-current intercepts inside of their
>> >rails. ECL is only one of them; perhaps you've heard of TTL?
>
>> I think Matt is asking that the zero current intercept be the same for
>> typ,min,max not that it be 0.
>
>Still wouldn't work. TTL (to pick one) intercepts when the
>forward current through the base-collector junction equals
>the pulldown current through the collector-emitter path.
>This depends on the forward voltage of the base-emitter
>junction, the beta of the transistor, and the forward
>voltage of the collector-base junction as well as the
>predriver current to the transistor base node (also variable).
>The first three are dependent on process and temperature, and
>the last is also dependent on supply voltage. IOW, the
>open-circuit Vol is going to be all over the place.

Excellent point DC!

Any ideas on how to do this that would work better are appreciated.
Did I mention it needs to be reasonably simply so it's not too hard
to write the test. This is another common problem we see it would be nice
to smash with the golden parser.

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Have a great day....
Kellee Crisafulli at HyperLynx
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 Wed Nov 4 14:07:10 1998