Re: [Q] off leak current?

Hello Akimoto:

The answer is 2. Clamp curves.

When the leakage current is significant, or
there are internal terminators, care must be
exercised in which clamp table the information
should be entered to avoid double counting.

1. If the leakage is to ground (or the lower rail),
then all of the leakage current should be put in
the [Gnd Clamp] and techically, the [Gnd Clamp]
range should be extended from -Vcc to 2 Vcc.

2. If the leakage is from Vcc than all of the
leakage current should be put into the [Power Clamp]
and its range also extended from -Vcc to 2 Vcc.

3. If the leakage is from both Vcc and Gnd paths,
then the appropriate leakage contributions should
be present in both the extended [Power Clamp]
and [Gnd Clamp] tables. This applies to internal
terminators as well.

Bob Ross
Mentor Graphics

akimoto@lsi.nec.co.jp wrote:
>
> I have a question about the IBIS modeling.
>
> Where should we put the off leak current into?
> 1) Both CLAMP curves and PULLUP/DOWN curves?
> 2) Only CLAMP curves?
> 3) Only PULLUP/DOWN curves?
> 4) Nothing? (Same as resistor?)
>
> I'm afraid how the board simulators get this information
> from IBIS model.
> Please, don't ask me more about the off leak current. ^_^
>
> Best regards,
> Akimoto
>
> ------------------------------------------------------
> Akimoto Tetsuya
> Design systems dep. System LSI Design Engineering Div.
> NEC Electron Devices, NEC Corporation
> Email:akimoto@lsi.nec.co.jp Phone:044-435-1513
Received on Thu May 25 17:45:48 2000