Re: Ramp Def. ??

Hello Bob and Stephen

        Thank you for your responses. Your answers are what I expected.
However, the IBIS specifications are not clear on that. In fact it defines
ramp rate in both ways. So we should make correction on the specifications.

Regards, Ahmed.

>>>> Bob Ross wrote:

Ahmed:

Case (b).

The 20% and 80% voltage points are 1.8 V and 4.2 V.

Best Regards,
Bob Ross
Interconnectix, Inc.

>>>> Stephen Peters wrote:

Hello Ahmed:

   It's the 20% to 80% of the voltage swing. Specifically
the Dt number is calculated as (for rising wavefront)....

(time at which voltage waveform crosses [.8(voltage swing) +
starting voltage]) - (time at which voltage waveform crosses
[.2(voltage swing) + starting voltage]).

         Hope that helps.

           Regards,
           Stephen Peters
           Intel Corp.

>>>> Ahmed Omer wrote:

Hello IBIS people

Is ramp rate defined as the time it takes the output to go:
(a) 20% to 80% of output final value
 or
(b) 20% to 80% of output voltage swing*

* I define voltage swing as the difference
  between final value and initial value.
 
For example;
Say, the output swings 1 to 5 volts. | 5 v ____
To calculate the ramp rate do I use | /
(a) 20% to 80% of 5 volts | /
 or | /
(b) 20% to 80% of 4 volts | 1v ____/
 
Regards, Ahmed.
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Received on Thu Oct 24 07:48:38 1996