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Is there anywhere I can download some current-voltage data for a bipolar junction transistor? (It doesn't matter that much which one.)

To explain further, for a simple BJT circuit we have the following variables. (Assuming NPN.)

  • Base-Emitter voltage bias
  • Base-Emitter current
  • Collector-Emitter voltage bias
  • Collector-Emitter current
  • Transistor HFE (beta) which is a function of temperature
  • Transistor temperature, which other variables such as the Collector-Emitter current, might have a second order effect from

I don't know if these are all independent - I believe they all are. Some might become dependent on each other if a complete circuit is drawn including an impedance on the base and collector (or emitter) nodes.

Are there any example devices which have (presumably large) tables of data available for download for measurements of these parameters?

  • Why do I want this?

I am interested in writing some simulations involving BJTs which requires more information than can be obtained from the typical transistor equations.

In other words, all of the non-linearities are important, and the behaviour in regions outside of as well as including the active region are also important. If some data source only has data for the active region, this is probably good enough.

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    \$\begingroup\$ From the manufacturer possibly. \$\endgroup\$
    – Solar Mike
    Sep 26, 2022 at 19:05
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    \$\begingroup\$ You could find a curve tracer and gather the data yourself, if you have the budget. You could probably find a Tek 370A for a few thousand bucks these days; it can save collected data to a 3¼" floppy disc, or send it over GPIB to anything that can communicate that way. \$\endgroup\$
    – Hearth
    Sep 26, 2022 at 19:14
  • \$\begingroup\$ @Hearth Out of budget unfortunatly - if nothing else I can get something very approximate with a couple of multi meters and enough time ... but there are automated ways of doing these things. Doing it by hand isn't really practical. \$\endgroup\$ Sep 26, 2022 at 19:25
  • \$\begingroup\$ >Transistor HFE (beta) which is a function of temperature< ... not only. It depends of Early voltage, of Ic current .... Some characteristics may only be known with pulsed currents ... And some simulators use ten's of parameters ... More then "typical" equations. \$\endgroup\$
    – Antonio51
    Sep 26, 2022 at 19:28
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    \$\begingroup\$ @user3728501: Have you got an Arduino? \$\endgroup\$
    – JRE
    Sep 26, 2022 at 20:09

1 Answer 1

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I am interested in writing some simulations involving BJTs which requires more information than can be obtained from the typical transistor equations.

Get a simulator (which uses dozens of parameters to model a transistor) and do some simple graphs like this one (for a 2N7002 MOSFET that I had to hand): -

enter image description here

Given that you are trying to make a homespun simulation tool, you might as well develop it along the recognized lines used by several vendors.

Micro-cap is free BTW and comes with hundreds of transistor models. If you get used to it you'll find a ton of things you haven't even thought of yet in your quest to develop a simulator tool. Alternatively you may decide that there's no point re-inventing the wheel.

All micro-cap graphs available with numerical output of course (same for LTSpice too I believe).

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