What is avalanche effect in diodes?

In electronics, an avalanche diode is a diode (made from silicon or other semiconductor) that is designed to experience avalanche breakdown at a specified reverse bias voltage. The Zener diode exhibits an apparently similar effect in addition to Zener breakdown.

What is avalanche effect Zener effect?

Zener Breakdown vs Avalanche Breakdown

What is the difference between Zener effect and Avalanche effect?

The main difference between Zener breakdown and Avalanche breakdown is the occurrence of their mechanism due to the high electric field….Difference between Zener breakdown and Avalanche breakdown.

What is avalanche and zener breakdown?

Avalanche breakdown occurs due to the rapid collision of electrons with other atoms. Zener breakdown occurs because of the high electric field. Zener breakdown is the controlled version of Avalanche breakdown in a modified p-n junction.

What is principle of Zener diode?

When a PN junction diode is reverse biased, the depletion layer becomes wider. After certain reverse voltage across the junction, the minority carriers get sufficient kinetic energy due to the strong electric field. …

What is meant by Zener breakdown?

The Zener breakdown can be defined as the flow of electrons across the p kind material barrier of the valence band to the evenly filled n-type material conduction band. The Zener breakdown generates electrons whereas the avalanche generates holes as well as electrons.

What is Zener effect?

The Zener effect is a type of electrical breakdown that occurs in a reverse-biased PN junction when the electric field enables tunnelling of electrons from the valence to the conduction band of a semiconductor, leading to a large number of free minority carriers which suddenly increase the reverse current.

At which voltage Zener breakdown occurs?

Zener breakdown voltage is found to occur at electric field intensity of about 3×107 V/m. Zener breakdown occurs in heavily doped junctions (p-type semiconductor moderately doped and n-type heavily doped), which produces a narrow depletion region.

What are the advantages of Zener diode?

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.

What is Zener breakdown voltage?

Breakdown voltage for commonly available Zener diodes can vary widely from 1.2 V to 200 V. For diodes that are lightly doped the breakdown is dominated by the avalanche effect rather than the Zener effect. Consequently, the breakdown voltage is higher (over 5.6 V) for these devices.

Is Zener diode reverse biased?

The Zener diode has a well-defined reverse-breakdown voltage, at which it starts conducting current, and continues operating continuously in the reverse-bias mode without getting damaged.

Why is Zener diode reverse biased?

Zener diodes are simply reverse-biased diodes that can withstand operating in breakdown. As the reverse bias voltage increases, Zener diodes continue to conduct a constant amount of current (the saturation current), until a certain voltage is reached. Breakdown voltages can range from 1 to 100 V.

How are avalanche diodes different from Zener diodes?

Avalanche diode. Both effects are present in any such diode, but one usually dominates the other. Avalanche diodes are optimized for avalanche effect so they exhibit small but significant voltage drop under breakdown conditions, unlike Zener diodes that always maintain a voltage higher than breakdown.

How is avalanche breakdown different from Zener breakdown?

Because the avalanche breakdown is uniform across the whole junction, the breakdown voltage is nearly constant with changing current when compared to a non-avalanche diode. The Zener diode exhibits an apparently similar effect in addition to Zener breakdown. Both effects are present in any such diode, but one usually dominates the other.

How does a Zener diode work in reverse breakdown?

A Zener diode operating in breakdown acts as a voltage regulator because it maintains a nearly constant voltage, which is equal to the Zener voltage, across its terminals over a specified range of reverse-current values. This constant voltage drop across the Zener diode produced by reverse breakdown is represented by a DC voltage symbol.

When does avalanche breakdown occur in a PN junction diode?

Avalanche breakdown occurs in a PN junction diode which is reasonably doped and has a thick depletion layer. It usually occurs when a high reverse voltage is applied across the diode. As we keep on increasing the reverse voltage, the electric field also keeps increasing.