What is a Zener Diode and How to use it?

A diode is a two-terminal device and one of the active device in the electronic devices. It is basic and simple to understand. Most of the diodes are made up of n-type and p-type semiconductor.
Before dipping into Zener diode let us define some parameters for a diode

  • Diode voltage – it is the voltage across the diode when the diode is operated in forward or reverse biased.
  • Diode Current – It is the amount of current flowing through the diode
  • Breakdown voltage – It is the reverse voltage which is applied to the diode at which a large amount of current start flowing through the diode and the diode burns out and it is of no use.

What is a Zener diode?

Zener diode is a special purpose diode that is made to operate in the breakdown region. Zener diode when used in reverse biased, it shows a sharp increase in reverse current when the voltage crosses the breakdown voltage and it is doesn’t burns out.

Zener Diode Symbol 1
Zener Diode Symbol

Every diode has a reverse breakdown voltage and it depends on the doping of the impurity atom. General-purpose diode and Zener diode are much similar except the breakdown region. Let us consider a V-I characteristic of a Zener diode.

Zener Diode Characteristics 1
Zener Diode Characteristics

In diode forward voltage, the diode is similar to the general-purpose diode. It has forward voltage sometimes called voltage drop across the diode.
In reverse voltage the diode act as open circuit before the diode breakdown voltage.

How to use Zener diode?

Zener diode is useful when it is used in reverse biased. First, identify the breakdown voltage of the diode by reading the datasheet of the diode carefully. Here are some uses of Zener diode.

1. Voltage regulation using Zener Diode

The Zener diode can be used to regulate voltage as it’s voltage remains almost unchanged when it is operating in breakdown region.

Voltage Regulation Using Zener Diode
Voltage Regulation Using Zener Diode

2. Waveform Clipping using Zener Diode

If peak voltage is exceeding the desired voltage then Zener diode can be use to clip off the undesired voltage.

Waveform Clipping Using Zener Diode
Waveform Clipping Using Zener Diode

3. Protection from unwanted voltage spike

Most of the Electronics devices can be damage because of voltage spike. By using Zener diode, the voltage spike is suppressed.

Unwantage Voltage Spike Protection
Unwanted Voltage Spike Protection using Zener Diode

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