[sdiy] 3083 graph fitting

[Aaron Lanterman]

On Thu, 4 May 2006 gt4430b at mail.gatech.edu wrote:

> How does this look?

Mark, this is pretty interesting. I'm going to forward this info to the 
SDIY list to see if they have any thoughts about my interpretation of your 
data.

It's odd that the curve tracer didn't spit out another column showing the 
ib, so we could sort out the different lines.

SDIYers - check out

users.ece.gatech.edu/~lanterma/ece4803/drafts/3083AQ1.pdf

Which I'm guessing are measurements of Q1 by the curve tracer, from 
3083 specimin A.

(Mark, I see you labeled the file 3803, you'll want to fix that so you 
don't get confused).

The top graph is a plot of all the points, vbe on x-axis and log(ic) on 
y-axis.

If you scroll way to the bottom, you'll see another plot where Mark zoomed 
in and tried to fit a line.

If we exponentiate your line, we get an Is of 5.1E-16; I really have no 
idea what to expect there, as I've never gotten an Is on a datasheet to 
match what I get when I try to fit points on a curve on a datasheet.

That 42.898 is interesting. Let's see if we take 1/Vt where Vt = 0.026, we 
get 38.46, which is pretty close to your 42.898, so that makes 
sense!

I know the curve tracer has a little lid you put over the system under 
test to keep out air currents and such... out of curiosity, did it also 
have a themature sensor so we could know what temperature things were 
taken at?

When you make the plots, I'd just plot points, and not try to have Excel 
connect lines between them, since the excel output of the tracer doesn't 
seem to give us a way to pick out individual lines.

  - Aaron

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Dr. Aaron Lanterman, Asst. Prof.
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