[SI-LIST] Driver Output Impedance am I doing this correctly?

Hi,
Thanks in advance for anyone taking the time to read
this, I know how valuable everyone's time is.  I'm
trying to calculate a number for our driver output
impedance that I can give to someone working with our
chip.  I'm relatively new at this so I was wondering
if my approach was flawed.  

My configuration is:

Driver --> BondWire --> Substrate Board Trace --> Ball

My driver's rise time is 500ps and my goal is to
calculate our total impedance value in order to allow
others to choose the appropriate series terminating
resistor.

Driver
1.) I used spice with a 50 Ohm load on the output and
Ohms law to get the real impedance of the driver
Zdriver (14.5Ohms).

BondWire
2.) I read through the SI archives and other docs and
then I assumed the inductance of the bondwire was
1nH/mm on a 2mm bondwire.  That means:

BondWire = 2nH

Then I took the Frequency of the output to be:
F = .35/Tr
F =  .35/500ps
F = 700Mhz

Then I used the impedance formula for an inductor (can
I do this with the F I calculated or does that not
make sense?).  

Z = 2pi * f * L 
Z = 2pi * 700Mhz * 2nH
Z = 8.8Ohms

Finally
So I figured that the Zdriver + Zbondwire +Zimag(I'm
missing that) would equal the output impedance of the
driver itself, and I know the impedance of the
substrate trace.

Does that make sense, or am I going about this all
wrong?  I still don't know how to calculate the
frequency dependant part of the driver output
impedance but I'm researching like crazy. 

Any feedback or new reference material would be
greatly appreciated.

Thanks,
Eric


                
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