Electrical Engineering ⇒ Topic : Avalanche Breakdown

Avalanche Breakdown

If the reverse voltage across the P-N junction increases, the electric field across the junction also increases (since, electric field = voltage/distance). The electric field imports the required high energy to a thermally generated carrier crossing the junction when the reverse bias magnitude reaches a certain level. The highly energetic carrier collides with the crystal ion on its way and disrupts a covalent bond. So, another electron-hole pair is generated. Therefore, the number of carriers is multiplied. A large number of carriers (electrons and holes) are generated within a very small time interval. This process is known as avalanche breakdown and a large reverse current is generated in this process.