[sdiy] Is parameter

[Aaron Lanterman]

The Is parameter is sort of a tricky thing anyway...

Let's talk about diodes for a second (to keep things simple)

If you try your usual diode equation

Is (e^(v/vt) - 1)

and try to fit points off of a I/V chart off a datasheet - it doesn't 
quite fit and match the params listed on the datasheet. If you use the Is, 
you don't get the curve on the sheet; if you fix Is as on the sheet and 
try to a fit vt do get something that's not what you expect and it doesn't 
line up along the curve...

I asked one my microelectronics about this - he said that Ebers Moll (or 
the standard diode model, or whatever) is itself just an approximation to 
much more complex behaviors.

- Aaron

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Dr. Aaron Lanterman, Asst. Prof.
and Demetrius T. Paris Junior Prof.    Voice:  404-385-2548
School of Electrical and Comp. Eng.    Fax:    404-894-8363
Georgia Institute of Technology        E-mail: lanterma at ece.gatech.edu
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