Question

What is a zener diode?

Answer 1

A Zener diode is a specialized type of semiconductor diode that is designed to work in reverse-biased mode, unlike regular diodes that are primarily used in forward-biased mode. When a diode is in forward bias, it allows current to flow through it, but in reverse bias, it typically blocks the flow of current.

However, a Zener diode is engineered to have a specific and well-defined breakdown voltage, also known as the Zener voltage (VZ). When the reverse bias voltage applied across the Zener diode exceeds its Zener voltage, the diode starts to conduct in reverse breakdown mode. This means that the Zener diode allows current to flow in the reverse direction, effectively "breaking down" and providing a controlled path for the current to pass through.

Zener diodes are commonly used in electronic circuits for voltage regulation and voltage reference applications. When connected in parallel with a load, they can maintain a constant voltage across the load, even if the input voltage fluctuates. This makes them useful for stabilizing power supplies and protecting sensitive components from voltage spikes.

The ability of Zener diodes to maintain a nearly constant voltage across their terminals during reverse breakdown makes them essential components in various electronic devices and circuits, ranging from voltage regulators and voltage references to surge protectors and overvoltage clamps.