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What happens when a diode reaches its breakdown voltage?
Neither of the two breakdown mechanisms is destructive. However heating caused by the large breakdown current and high breakdown voltage causes the diode to be destroyed unless sufficient heat sinking is provided.
What is avalanche breakdown and Zener breakdown?
Hint: There are two types of breakdowns in p-n junctions. 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.
Is Zener effect and zener breakdown are same?
The Zener effect is distinct from avalanche breakdown. 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.
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.
How does the avalanche effect occur in a Zener diode?
The avalanche effect occurs in both rectifier and zener diodes at a sufficiently high reverse voltage. Zener breakdown occurs in a zener diode at low reverse voltages. A zener diode is heavily doped to reduce the breakdown voltage. This causes a very thin depletion region. As a result, an intense electric field exists within the depletion region.
What happens to the junction during a Zener breakdown?
The reverse current starts flowing in the junction because of which depletion region entirely vanishes. This process is known as the Zener breakdown. In Zener breakdown, the junction is not completely damaged. The depletion region regians its original position after the removal of the reverse voltage.
What is the breakdown voltage of a diode?
The breakdown voltage,commonly called the Zener voltage, is the reverse-biased voltage that causes the diode to conduct current. Breakdown voltages usually range from 2.4 V to hundreds of volts. 2. Test Current (IZ) For each Zener diode, the Zener voltage (V Z) is measured at a specified Zener test current (I Z ).