Diodes With Hats: Zener and Schottky

For beginners, diode types can sometimes be a bit of mental gymnastics. If all it does is act like a magic pixie check valve, why are there so many kinds? Schottky diodes are typically  hard to mentally set apart from the standard when described by a data sheet. Zener diodes can be downright baffling for beginners, especially when mistakenly thrown in a circuit in place of a regular 1N4001. [Afrotechmods] put together a great video explaining their difference and use cases.

In both videos he does an excellent job of describing the pros and cons while setting up experiments to exhibit each. For the Schottky it’s the faster switching and lower voltage drop. For Zener it’s less about the cons and more about exploiting its strange configuration for voltage clamps, regulators, and making expensive guitars sound bad with audio distortion circuits.

He finishes both videos with good design tips for selecting and using the parts as a burgeoning circuit designer. Diode data sheets should be less of a mystery afterwards.

14 thoughts on “Diodes With Hats: Zener and Schottky

  1. The one thing I’d say about Schottky diodes is that it’s not exactly that their reverse leakage current is higher – it just *varies wildly* compared to a normal silicon diode, which is almost always “nano-amp scale, don’t worry about it.”

    A BAS70, at room temperature, is in the ~10s of nA reverse leakage current, which is basically the same as a silicon diode (gets much worse at higher temperatures, as mentioned in the video). A 1N5822, though, has tens of uA, over 1000 times higher.

    So it’s not like you can’t use them in a peak detector circuit; you just need to choose carefully.

    1. Many, many years ago, I confused zeners with 1N4148s…. had a bargain bag of surplus diodes and most of them were unmarked zeners, thought they were 1n4148 equivalents though… tried using them for decoding/multiplexing, didn’t work too well.

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