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lcamtuf's avatar

And yep, to preempt the inevitable comment: we used to have even more specialized devices, called "curve tracers", that were designed specifically for making V-I plots. They're more or less extinct now because SMUs can do the same job (including models that go to 200 V, 1,000 V, or even 3,000 V).

Chuck's avatar

Very nice work. One of the things I discovered about MOSFETs when building my BattleBots speed controller is that the Rds value changes nearly 100% between 25 degrees C and 150 degrees C. That is also generally plotted in the data sheet. It would be interesting with your setup to see how closely 'real' that spec is.

lcamtuf's avatar

I've been thinking about it, I have a hotplate with a temperature probe, so it wouldn't be hard.

Gary F Dirkse's avatar

Great work! I am waiting for your new book. I noticed that text book curves don’t agree with oscilloscopes for power supplies. Seeing the truth is what I desire even if, the text book curves are ideal.

Alexandre Gomes's avatar

Shared the diode saturation curve on LinkedIn and X referencing the blog post - hope you don’t mind.

Thanks for sharing your work - I really enjoy this kind of content.

Adrian Bergeron's avatar

I actually understood virtually all of this, rather than the 1-2% I kind of grasped in many of your other writings - that's my lack of knowledge, and in no way your fault.

Always interesting, in any case.

lcamtuf's avatar

Thanks. And FWIW, if some of the articles are over your head, I don't mind if you want to ask questions or suggest more basic topics. It's not like I have a strict line-up of topics to cover or that I decided you need to be this tall to read the blog.

Adrian Bergeron's avatar

No problem, I think I prefer dipping my toes into whichever topics that have grabbed your interest at the moment - the obvious downside to being a professional Jack-of-all-trades/generalist is nearly always being in at least slightly over my head.