RE: On chip Active termination

From: Ingraham, Andrew <Andrew.Ingraham@compaq.com>
Date: Mon Apr 16 2001 - 11:34:18 PDT

... if I look at the GND clamp curve I observe ~ 0mA
> current at 1.3V ( which is the valid voltage level with the output
> tristated).
 
This may not be directly related to your question....

I am just curious whether it is appropriate to put your active termination
in the [GND clamp] curve.

If a supply voltage is involved in this on-chip termination, then the I/V
characteristics would vary with the supply voltage. Putting the termination
I/V data in only the [GND Clamp] table means that it would not vary with
supply voltage, in the IBIS model.

If the termination is (or behaves like) something other than a resistance to
just the supply, then you could split the termination current between the
[GND Clamp] and [POWER Clamp] tables, to make the model more accurate.

Sorry if this is what you have already done.

Regards,
Andy

 
Received on Mon Apr 16 11:36:11 2001

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