Cursed circuits #6: reverse avalanche oscillator
29 points
4 days ago
| 3 comments
| lcamtuf.substack.com
| HN
voidUpdate
1 hour ago
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You can even use it to make a simple audio synth: https://www.lookmumnocomputer.com/simplest-oscillator
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mock-possum
47 minutes ago
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The man is a treasure
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cryo32
1 hour ago
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This isn't particularly cursed. I mean we've had avalanche pulse generators for well over half a century easily. It's just exploiting semiconductor characteristics they don't teach you in the usual garbage undergrad textbooks.
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denotational
58 minutes ago
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> the usual garbage undergrad textbooks

Out of interest, please could you give some examples of textbooks you consider garbage, and some you consider not to be (undergrad or otherwise)?

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cryo32
48 minutes ago
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Garbage -> Sedra and Smith particularly - hate it, anything which kicks you in the nuts right up front with Laplace and networks abstractions, anything from Pearson - have never seen a good one.

Good -> Razavi (Fundamentals of Microelectronics), Art of Electronics, most Jim Williams stuff (AN's and articles), Bowick RF Circuit design. They're actually useful.

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SAI_Peregrinus
31 minutes ago
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I find Sedra/Smith a terrible introduction, but a good reference. It's nice once you've already built an intuition for how things work to be able to go back & build up the mathematical models, but trying to understand the behavior of circuits from the math first is a bad order.
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fnands
1 hour ago
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Delightfully cursed.

I wonder how consistent the breakdown voltages are between manufacturers? I mean, I am sure there is some spec, but is it not just a minimum in this case?

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