What is the primary function of a Zener Diode in a circuit?

The primary function of a Zener diode in a circuit is to limit voltage to a certain level. Zener diodes are designed to allow current to flow in the reverse direction when the voltage reaches a specified breakdown value, known as the Zener voltage. This property makes them ideal for voltage regulation applications, where maintaining a stable voltage output despite variations in input voltage or load current is essential.

When a Zener diode is connected in reverse bias, it effectively clamps the voltage across it to the Zener voltage, preventing it from exceeding this level. As a result, the Zener diode can protect sensitive components in a circuit from overvoltage conditions and ensure that the voltage remains within a specified range. This function is critical in power supply circuits, voltage reference applications, and transient suppression scenarios.

Other options, while related to diodes, do not capture the unique role of a Zener diode. For example, rectifying AC current refers to converting alternating current to direct current, a function typically performed by standard diodes. Amplifying signals pertains to active devices like transistors, rather than Zener diodes, which do not amplify; they regulate. Maintaining constant current is a function associated with devices like current regulators or specific circuit designs, which