What is the function of a Zener diode in an electric circuit?

A Zener diode functions primarily as a voltage reference in electric circuits. It is designed to allow current to flow in the reverse direction once the voltage across it reaches a specific level known as the Zener breakdown voltage. This unique property makes Zener diodes highly effective in providing stable voltage levels. In applications, they are often used in voltage regulation circuits, ensuring that the output voltage remains constant despite variations in input voltage or load conditions.

While current regulation is an important function in some devices, the direct role of a Zener diode aligns closely with maintaining and providing a fixed voltage reference. This stability is crucial in circuits where precise voltage levels are necessary, such as in reference voltages for analog-to-digital converters or during the design of power supply circuits. Signal amplification and rectification are roles served by other types of diodes or components, further clarifying that the Zener diode's primary characteristic is its ability to maintain a consistent voltage across its terminals.