Definition and Function of Zener Diode – Diode Zener is an Electronic Component made of Semiconductors and is a type of Diode specifically designed to be able to operate in reverse bias circuits. When paired to the Forward Bias Circuit, the Zener Diode will have the characteristics and functions of a Normal Diode in general. This type of diode effect was discovered by an American physicist named Clarence Melvin Zener in 1934 so that the name diode is also taken from the name of its inventor, Dioda Zener.
Zener Diode Shapes and Symbols
Below are the shapes and symbols of the Zener diode:
Working Principles of Zener Diode
Basically, the Zener Diode will channel the electric current flowing in the opposite direction if the voltage given exceeds the limit of “Breakdown Voltage” or Translucent Voltage of the Zener Diode. This characteristic is different from ordinary diodes that can only channel electric current in one direction. This Breakdown Voltage is also called Zener Voltage.
For more details about the Zener Diode, let’s take a look at the basic network of Zener Diodes below:
In the circuit above, Zener Diode is installed with the principle of Reverse Bias, the circuit is a common way in the installation of Zener Diode. In the circuit, the input voltage (entry) given is 12V but multimeter shows the voltage passing through the Zener Diode is 2.8V. This means that the voltage will drop when passing through the Zener Diode installed in Reverse Bias. While the function of resistors in the circuit is for electrical current limiting. To calculate the Electric Current (Ampere), we can use Ohm’s Law as below:
(Vinput – Vzener) / R = I(12 – 2.8) /460 = 19.6mA
If you use a higher voltage, for example 24V. Then the electric current flowing in the circuit will be greater:
(24 – 2.8) / 460 = 45mA
However, the voltage passing through the Zener Diode will be the same at 2.8V. Therefore, Zener Diode is an Electronic Component suitable for use as Voltage Regulator, Zener Diode will provide a fixed voltage and in accordance with its Zener Voltage against the given Input Voltage.
In general, zener diode voltage available in the market ranges from 2V to 70V with power (power) from 500mW to 5W.
To calculate the dissipation of Zener Diode power, we can use the formula:
P = Vz I
Example:
P = 2,8 x 19,6P = 54,9mW
Read also Diode function and how to measure it
Zener diodes are usually applied to Voltage Regulators and Over Voltage Protection. The function of the Zener Diode in such circuits is to stabilize current and voltage.
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