Re: [SI-LIST] : Does IBIS describe output transition which both MOS turned on?

Vinu Arumugham (vinu@cisco.com)
Tue, 12 May 1998 22:56:12 -0700

John,

IBIS models also have V/T curves. These should cover overlapped
conduction.

Vinu

John Lin - TAO wrote:

> Dear IBIS fans/SI Experts,
>
> As I know for a CMOS device, during output transition, both PMOS and
> NMOS will turn on in a short period of time. I wonder if an IBIS model
> describes this behavior. If yes then how it does. Will the behavior
> affect the accuracy of simulation with IBIS model?
>
> Based on what I know the V-I curve for PULL UP or DOWN is obtained by
> turning one MOS off and then swift the V-fixture to get Current reading.
> It seems to me that the V_I curve doesn't contain the information to
> describe the transition, both PMOS and NMOS turned on.
>
> Any comment?
>
> Thanks,
>
> JOHNLIN
> CAE Engineer of EDA Department
> Digital Equipment Corp. Taiwan Branch
> Email: Linjohn@mail.dec.com <mailto:Linjohn@mail.dec.com>
> TEL: 1-886-3-3900000 ext. 2152