Andrey

IBIS package parameters usage

Discussion created by Andrey on Aug 12, 2011
Latest reply on Sep 8, 2011 by david.royle

Hello everyone.

 

I tried to understand the way IBIS package parameters (Rpkg, Cpkg, Lpkg) are used in HyperLynx. I simulated the following circuits:

 

schematic.jpg

In the IBIS model assigned to the U1.1 buffer Rpkg/Cpkg/Lpkg are set to 0.0

To the U13.1 buffer the same model was assigned but its pkg parameters were the following: Rpkg = 0.9, Cpkg = 4pF, Lpkg = 3nH

 

I expected to get similar waveforms but the waveforms appeared to be markedly different:

 

hyperlynx.jpg

hyperlynx_f.jpg

hyperlynx_r.jpg

hyperlynx_opt.jpg

 

Why the waveforms are so different?

Is it correct to expect the waveformes to be similar?

How IBIS packaged parameters are utilized?

What is an equivalent circuit of the U13.1 buffer (IBIS model with defined pkg parameters)?

 

Thanks,

Andrey

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