On Non-Monotonic Drivers

To All:

Based on the discussions and clarifications, I would conclude that

(1) IBIS Version 2.1 provides a format which can legally characterize the
IV curves. It also could characterize resulting waveforms for given
test loads, although I have not seen details on the dynamic switching
characteristics and possible artifacts.

(2) From what has been stated, some simulation approaches would not have
have difficulty with the VI non-monotonicity.

The real concerns are:

(1) Different simulators may take different approaches including filtering
the data to produce significantly different simulations. (However, if
we do not have access to source data, we cannot validate that any of
the approaches will produce an acceptable simulation.)

(2) There exists a well-defined feedback reason for producing this type
of non-monotonicity. So the correct simulation MAY depend on knowing
exactly the mechanism. The simulators may have to include the mechanism,
and IBIS may need to be extended to characterize it by its parameters.

The questions I have are:

(1) Is there a way to accurately characterize the mechanism without revealing
the proprietary details from a black box point of view? What are its
critical parameters?

(2) Because there exists a negative resistance region, are there any load
constraints associated with the technology (e.g., an impedance range)?

(3) Could a simplified Spice test case be revealed which illustrates
the effect, and from which simulation approaches could be checked?

Bob Ross,
Interconnectix, Inc.
Received on Thu Aug 31 18:03:28 1995