Created at: 2025-02-02
Zeners are used to create a constant voltage inside a circuit somewhere, simply done by providing them with a (roughly constant) current derived from a higher voltage within the circuit.
However...
When thinking about zeners, it’s worth remembering that low-voltage units (e.g., 3.3 V) behave rather poorly, in terms of constancy of voltage versus current (Figure 1.17); if you think you need a low voltage zener, use a two-terminal reference instead (also called IC voltage reference).
See my notes on zener diodes for more info.
Preferred over zener diodes for low voltages.