Zener Diode Working Principle

January 23, 2024 Post a Comment

Zener diode working principle

A Zener diode operates just like a normal diode when it is forward-biased. However, a small leakage current flows through the diode when connected in reverse biased mode. As the reverse voltage increases to the predetermined breakdown voltage (Vz), current starts flowing through the diode.

What is Zener diode and its application?

Zener diode is a semiconductor device consisting of a P-N junction which conducts the current in reverse direction when a certain specified voltage is reached. It has a reverse breakdown voltage which means it can continuously operate in a reverse-bias mode without getting damaged.

What is the working principle of diode?

Main functions The most common function of a diode is to allow an electric current to pass in one direction (called the diode's forward direction), while blocking it in the opposite direction (the reverse direction). As such, the diode can be viewed as an electronic version of a check valve.

How does a Zener diode work in reverse-bias?

Zener diode is a highly doped diode. It behaves like a normal diode in forwarding bias. When the Zener diode is reverse biased the junction potential increases. When the diode's breakdown voltage is reached at which point a process called avalanche breakdown occurs in the depletion layer of the semiconductor.

What is Zener voltage called?

Voltage regulator diodes actively use this characteristic. Since this breakdown voltage is also called Zener voltage, voltage regulator diodes are also called Zener diodes. This voltage may be used as a constant voltage power supply or a reference voltage for electronic circuits.

What is Zener diode symbol?

In zener diode, electric current flows from both anode to cathode and cathode to anode. The symbol of zener diode is similar to the normal p-n junction diode, but with bend edges on the vertical bar.

What is Zener diode characteristics?

Zener Diode Characteristics. Zener diodes operate similarly to conventional diodes when in the forward-bias mode. They have a bias turn-on voltage of between 0.3 and 0.7V. When connected in the reverse mode, there is a small leakage current flow in most applications.

What is breakdown voltage?

Breakdown voltage is the threshold voltage at which the initiation of breakdown occurs. However, before current can flow, the open gap voltage increases until it has created an ionization path through the dielectric. Once the current starts to flow, voltage drops and stabilizes at the working gap level.

What is the difference between rectifier and Zener diode?

Zener diode can provide a stable reference voltage. These diodes can be operated in reverse biased and break down at a certain voltage. These diodes are mostly used in power supplies to provide a reference voltage. A rectifier is a device that is used to convert an AC voltage to DC voltage.

What is the unit of diode?

For silicon diodes, the forward barrier potential is 0.7 volt and for germanium diodes, it is 0.3 volt.

What are the 3 main uses of diodes?

Some of their most common applications include turning AC to DC, isolating signals from a supply, and mixing signals. A diode has two 'sides' and each side is doped differently.

What are the 5 general types of diodes?

Types of Diodes

Light Emitting Diode.
Laser diode.
Avalanche diode.
Zener diode.
Schottky diode.
Photodiode.
PN junction diode.

Why Zener diode is highly doped?

Why is the p-n junction of the zener diode heavily doped? The p-n junction of the Zener diode is heavily doped to get a narrow depletion region. The narrow depletion region allows the ions to easily gain energy from the external source. In the reverse bias, the junction potential of the Zener diode is increased.

What are the advantages of Zener diodes?

Advantages of Zener Diodes

Less expensive than other diodes.
Ability to shift voltage.
Easily compatible and obtainable across systems.
High-performance standard.
Protection from over-voltage.
Ability to regulate and stabilize circuit voltage.
Greater control overflowing current.
Usable in smaller circuits.

Why Zener diode is used as a voltage regulator?

The Zener diode is often in use as a voltage regulator, primarily because the voltage drop across the diode is constant. Furthermore, the supply voltage must exceed the Zener voltage for the circuit to operate. Thereby, any electronic component connected in parallel with these diodes will have the same applied voltage.

Where is Zener diode used?

Zener diodes are used for voltage regulation, as reference elements, surge suppressors, and in switching applications and clipper circuits. The load voltage equals breakdown voltage VZ of the diode. The series resistor limits the current through the diode and drops the excess voltage when the diode is conducting.

Why is it called Zener diode?

A Zener diode is a type of diode that permits current to flow in the forward direction like a normal diode, but also in the reverse direction if the voltage is larger than the rated breakdown voltage or "Zener voltage". The device was named for Clarence Zener, who discovered this electrical property.

What is Zener region?

There is a point where the application of too negative a voltage will result in a sharp change in silicon diode characteristics, as shown in Fig. 1.1. The current increases at a very rapid rate in a direction opposite to that of the positive voltage region.

How is Zener voltage calculated?

It's knee current, breakdown current, or minimum current is 0.25 mA. The maximum current is calculated by dividing the power rating by the Zener voltage: I=P/V = 3W/12V = 0.25A.

Which side of Zener diode is positive?

In a perfectly ideal diode, current flows in one direction only, from the anode (positive side) to the cathode (negative side) which is marked with the stripe. The schematic symbol is a triangle pointing towards a bar, where the current flows in the same direction, towards the barred (striped) end.