Subject: Ramp Rates

From: [email-masked] (John Berrie)
Date: Mon, 20 Mar 95 12:11:34 GMT

Dear IBISians,
1. Can anyone clarify the convention for the dV/dT values for the ramp
characteristics. It is of course necessary to extract rise or fall time in
order to get dV/dT, but is the value for dV necessarily the actual voltage
transition when the output is being measured with a standard load ? In
other words, if a device had a 20%->80% transition time of 2nS with a
transition voltage of 5V, would 2.5V/1nS be allowed as an equally valid
entry as 5V/2nS. The reason I ask is that when looking at the line
formula-based in the frequency domain, the upper frequency of concern is
0.35/Tr which is a useful figure to be able to derive easily and
approximately.

2. Any information on IBIS model availability, now or in the near future,
free or for sale, would be most welcome.

Thanks in advance for your help.

Best Regards,

John 

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John Berrie, Chief Application Engineer    
Zuken-Redac Limited,                                                    
Green Lane,Tewkesbury,
Glos. GL20 8HE, England
Tel: (44) 01684 294161
Fax:(44) 01684 299754
E-Mail [email-masked]
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