Why does reverse current increase in reverse breakdown region?

When the reverse bias voltage becomes equal to zener voltage (i.e. V=Vz), then the electric field strenth across the junction becomes quite high. The movement of these electrons across the junction accounts for high current which is observed at the break down reverse voltage.

Why does reverse current show a sudden increase?

When the reverse voltage across the p-n junction reaches a critical voltage, the reverse current suddenly rises to a large value. It is due to sudden increase in the number of minority charge carriers, resulting breakdown of the diode.

What happens if the reverse current is increased above the breakdown value?

As the reverse voltage applied to the Zener diode increases, it reaches the breakdown voltage at which Zener current increases to a large value. In the breakdown region, further increase in reverse voltage will not increase the voltage across the Zener diode, it only increases the current.

What happens when the diode reaches its breakdown point during reverse bias?

“Break down” of a diode occurs during its reverse biased condition. We all know, under reverse bias the positive terminal of battery is connected to n side and the negative terminal of battery is connected to p side. At a point which we can call as “breakdown point”, the diode will get damaged.

Why does a reverse breakdown occur?

Zener breakdown occurs because of the increase in the electric field. High electric field increases break the covalent bonds which result in the increase of charge carriers. In Avalanche breakdown, the velocity of the minority carriers is increased by the increase in the electric field.

What causes reverse breakdown?

Avalanche breakdown is a phenomenon observed in a p-n junction diode in reverse bias. When a large reverse bias voltage is applied across a p-n junction diode, thermal current starts increasing to a large value. This results in the heating of the diode.

Why is the current under reverse bias almost independent?

When a p-n junction is reverse biased, a very small current (of the order of few μA) flows due to drifting of minority charge carriers whose number density remain constant upto the critical voltage. As result of it, the current under a reverse bias is almost independent of the applied potential upto critical voltage.

What is the cause of reverse breakdown voltage?

High electric field increases break the covalent bonds which result in the increase of charge carriers. In Avalanche breakdown, the velocity of the minority carriers is increased by the increase in the electric field. More covalent bonds are broken during the travel. This produces a high reverse current.

When reverse breakdown occurs in a diode?

Normally, the reverse current in a diode is very weak. If the external bias voltage is raised, the reverse current dramatically increases at a given reverse bias voltage value. This unique reverse bias voltage value is known as the breakdown voltage.

What is a reverse breakdown?

What It Is: Reverse breakdown voltage is the reverse anode voltage at which the diode conducts a specified amount of reverse current. Since it’s the reverse current across a junction, IR exhibits a knee shaped rise, increasing rapidly once breakdown occurs.

Why does reverse breakdown occurs in a diode?

Why does the reverse voltage increase at the break down junction?

The movement of these electrons across the junction account for high current which is observed at the break down reverse voltage. Specially if u observe in the case of zener diode, a sudden increase in reverse current happens.

Why does the reverse current increase in a Zener diode?

Reverse current increases as the diode behaves as short circuit after depletion layer width increases beyond a certain extent. Avalnache breakdown takes place In case of zener diode the reverse break down occurs when the diode reaches it’s breakdown voltage..

What is the meaning of reverse current?

Reverse current is when there is a higher voltage at the output of a system than at the input, causing current to flow backwards through the system. There are two common sources of reverse voltage: (1) when power is disconnected from a system and (2) when the body diode of a FET becomes forward- biased.

What happens when voltage is increased in a diode?

If we increase the voltage further to this breakdown voltage,the diode gets overheated and gets shorted because of the avalanche breakdown around the junction. Even though, the voltage remains the same almost, the current increases tremendously which may result in the failure of the diode.