Zener Diode as Voltage Reference: Working & Advantages

Introduction : Voltage references provide stable voltages irrespective of supply or load variations. Zener diodes are commonly used for this purpose because of their well defined reverse breakdown voltage.

Zener diode based voltage reference circuit working

As we know precision voltage references provide stable, accurate voltage standards for ADCs, analog circuits, references and calibration systems.

The figure-1 depicts simple circuit to get constant voltage across zener diode. This diode is used to maintain constant voltage across terminals when reverse current exceeds knee current.

Advantages of Zener diode

Following are some of the benefits of Zener diode.

1. It can maintain nearly constant voltage across load even when input voltage or load current varies. It is ideal for simple voltage regulator.
2. It provide stable and known breakdown voltage. This can be used as reference in precision circuits such as ADCs, Amplifiers etc.
3. When the voltage exceeds the Zener voltage, the diode conducts in reverse to clamp the voltage. This helps to protect components from spikes or surges.
4. They are inexpensive, widely available and easier to integrate.
5. They are manufactured with many different breakdown voltages which help designers to choose the one that closely matches their requirement.

Conclusion: Zener diode references are foundational in providing stable voltage in power supplies, instrumentation and control circuits.