I'm aware of how Zener diodes can work as voltage clamps, but how do TVS diodes work in terms of physical construction?
The Wikipedia article explains what they are used for, and a bit about their capabilities and parameters, but doesn't really explain how they're constructed or what their detailed physical behaviour is.
Is there a way to describe them with a discrete representation, or are they a unique construction?
Best Answer
In theory (in the land of spherical cows), TVS diodes are the same as other Zener diodes.
In practice, Semtech says:
In other words, normal Zener diodes are designed for a small current (i.e., with a small junction area), which flows continuously. The larger junction in TVS diodes can endure much larger breakdown currents, but only for a short time.
Furthermore, normal Zener diodes are designed to get an accurate breakdown voltage at a specific current. TVS diodes have somewhat looser tolerances, but this does not matter because they have to handle wildly varying currents, and the voltage varies with current anyway. (This is not as much a difference in construction but in testing.)
Bidirectional TVS diodes are constructed as two diodes connected back-to-back (often on the same die). Such a construction would not make sense for voltage-regulating Zener diodes.