Cursed circuits #6: reverse avalanche oscillator

(lcamtuf.substack.com)

23 points | by surprisetalk 4 days ago

3 comments

  • voidUpdate 1 hour ago
    You can even use it to make a simple audio synth: https://www.lookmumnocomputer.com/simplest-oscillator
  • cryo32 1 hour ago
    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.
    • denotational 39 minutes ago
      > 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)?

      • cryo32 29 minutes ago
        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.

        • SAI_Peregrinus 12 minutes ago
          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.
  • fnands 50 minutes ago
    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?