[IBIS-Users] Re: IV table voltage range for min max and typ corners

From: Sudarshan H N <hn.sudarshan_at_.....>
Date: Thu Oct 11 2007 - 22:01:48 PDT
Hi Arpad,

Thanks for your answers.

You didnt answer my question completely. For the first question, i wanted to
know what is the voltage range we need to consider in the IBIS file. Even
with your suggestion, how do we put the curret values from 6.3 to 6.6 in min
case and -3.0 and -3.3 max case as we always put one voltage range which
correesponds to -3.3 to 6.6.(i.e, typ voltage range).

Also what is the logic behind in taking voltage as 6.6 below, and 3.3 above
Vcc.  What i have understood is , this range corresponds to -Vdd to +2Vdd to
take care of short circuit and open circuit conditions that we see in the
transmission line. If the voltage changes either to max or min even this
condition should also change.

I wrongly typed as R_ref for my second question. I know the significance of
both R_fixture and R_ref and i actually meant R_fixture.  Here also , my
question is,  should rising and falling waveforms should cross Vmeas ?

Let me know your answers.

Thanks & Regards
Sudarshan

On 10/11/07, Sudarshan H N <hn.sudarshan@gmail.com> wrote:
>
> Hi Experts,
>
> In IV tables (clamps, pullup and pulldown), how do we normalize the
> voltage range correspoding to typical votage.
> If we take 3.3 V domain, we need to simulate for -3.3 to 6.6 for typical
> case, -3 to 6 for min and - 3.6 to 7.2 in max.
> Do we need to extrapolate the values in case min corner to get 3.3 to 6.6range ?
>
> With respect to V-t curves, we can take Rref as 50 ohm and generate the
> V-t curves. But the settling voltage may be less
> than the Vmeas (half of Pad voltage) (in case of rising waveforms). Is it
> acceptable ?
>
> Let me know your answers.
>
>
> Regards
> Sudarshan
>

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Received on Thu Oct 11 22:02:12 2007

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