Subject: Re: Bus Clamp vs Dynamic Clamp

From: [email-masked]
Date: Thu, 9 Mar 2000 14:58:44 -0600

As long as we're on the subject, what determines the current-voltage
behavior of a dynamic clamp in triggered mode once it's on?  Is the [GND
Clamp] keyword defined under the [Submodel] intended to supply the IV
characteristics of the ground dynamic clamp?  And the [GND Pulse Table] is
supposed to supply a voltage offset to the [GND Clamp] table for each point
in time that the clamp is on?  So if I'm a simulator and I notice that Vpin
has tripped V_trigger_f, I calculate Vpin-Vpulse and dump the current that
I find at the corresponding entry in [GND Clamp]?

Sounds like some stuff I can't measure directly from the pin, right?

Greg Edlund
Advisory Engineer, Critical Net Analysis
IBM
3650 Hwy. 52 N, Dept. HDC
Rochester, MN 55901
[email-masked]

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From: Bob Ross <[email-masked]>
Date: Fri, 10 Mar 2000 12:52:36 -0800

Greg:

I have some brief responses are in your text.

Bob Ross
Mentor Graphics

[email-masked] wrote:
> characteristics of the ground dynamic clamp? 

Yes?  This supplies the characteristics of a clamp portion that may be
shifted in time.

> And the [GND Pulse Table] is
> in time that the clamp is on?  

Yes

> So if I'm a simulator and I notice that Vpin

I do not understand this question.

> Sounds like some stuff I can't measure directly from the pin, right?

You can measure the combined effects, but you may not have information
from measurement that can decompose the effects into the mainline
and submodel elements.  This along with some other keywords are to
provide models by construction to emulate some known effects that
might be extracted or known by decomposing a buffer circuit.