most sensitive circuit elements? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: November 26, 2019, 04:01:06 am
content: What is the most sensitive circuit element that you can think of in terms of being able to handle some kind of power ?I know bare signal FETs are very sensitive to ESD, but I mean in a properly hooked up system that has a generator of some sort connected to it giving it a steady state signal that slowly rises.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: November 26, 2019, 04:15:52 am
content: Not sure exactly what you're driving at here but mixer/sampling diodes are pretty easy to blow.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 26, 2019, 04:58:19 am
content: Easy: a transistor, in the smallest possible feature size (a few nm across?), in the lowest melting point semiconductor that's still capable of transisting at room temperature say.I wonder what the ratings of superconducting elements are (Josephson junctions and whatnot)?Tim

author: coppercone2
author_rank: Super Contributor
timestamp: November 26, 2019, 05:49:48 am
content: what manufactured commercially used device comes closest? like, a component with a input, not something buried inside of a CPU thats inaccessible by any reasonable means.is there some notorious transistor family etc?

author: Gyro
author_rank: Super Contributor
timestamp: November 26, 2019, 09:59:56 am
content: This is a ridiculous question without knowing what circuit the element is used in. Sensitive parts may well be well protected by surrounding components (even resistor choices). In a properly designed circuit any part may fail before the 'most sensitive' one.It's impossible to say without any context!EDIT:Quote from: coppercone2 on November 26, 2019, 04:01:06 am

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 26, 2019, 11:33:20 am
content: Weren't tunnel diodes really sensitive? Low voltage, a small (low capacitance) part would be fairly vulnerable.RF parts are the smallest single components you can find. YMMV on ESD or power sensitivity.Back in the day, 3N138 was supplied with a wire ring shorting the leads together. Not necessarily vulnerable to power, but it didn't take much ESD to kill.Also, arguably, power in what sense, because a gate has a quite high impedance at low frequencies, so with suitable matching, it won't take much signal power to damage. This is something of a contrived case, as it's hard to make coils with high enough Q at say 1MHz for this to be much of an issue.Damage from mW? Seems plausible. But again, it's not a very motivating question because one can always make a smaller part and claim it's the most sensitive.Matter of fact, I think I'll exhale some H2O molecules, claim that they are circuit elements in the EM waves over my bench, and push their hydrogen nuclei into another spin state with a single VLW photon...Tim

author: mikerj
author_rank: Super Contributor
timestamp: November 26, 2019, 02:07:42 pm
content: Gunn diodes are extremely sensitive to ESD and excursions outside of their rated bias voltage.

author: ejeffrey
author_rank: Super Contributor
timestamp: November 26, 2019, 09:42:17 pm
content: Josephson junctions can be quite varied, but a typical one might blow out at around 1v. That is maybe more sensitive than most semiconductors, but not by that much. It is a thin oxide barrier so the physics is pretty much the same as with gate oxides, just a bit thinner than most--this is intentional as Josephson junction need to allow tunnelling current while it is desirable for transistor gates to not leak.

author: coppercone2
author_rank: Super Contributor
timestamp: November 27, 2019, 01:59:26 am
content: Quote from: Gyro on November 26, 2019, 09:59:56 amUsually if you add protection to a part its performance is degraded, armor is always a trade off. By properly hooked up I mean, not like you need to de-cap an ic and use advanced semiconductor techniques to access a node. I figured it would be obvious.. I thought a circuit designer might put something inside of a chip that was very sensitive if its protected by loads of different tougher circuits that will attenuate harmful things.I do understand the question is absurd, since the typical application might assume certain parts are used with the device.. but still