DIFFERENCE BETWEEN ZENER BREAKDOWN AND AVALANCHE BREAKDOWN:
So What is Zener Breakdown?
The Zener effect is a type of electrical breakdown in a reverse biased p-n diode in which the electric field enables tunneling of electrons from the valence to the conduction band of a semiconductor, leading to a large number of free charge carriers, which suddenly increase the reverse current. Zener breakdown is employed in a Zener diode.
Avalanche Breakdown?
Avalanche breakdown is a phenomenon that can occur in both insulating and semiconducting materials. It is a form of electric current multiplication that can allow very large currents within materials which are otherwise good insulators. It is a type of electron avalanche. The avalanche process occurs when carriers in the transition region are accelerated by the electric field to energies sufficient to free electron-hole pairs via collisions with bound electrons.
THE ABOVE FIGURE SHOWS THE I-V CURVE FOR A DIODE SHOWING AVALANCHE AND ZENER BREAKDOWN.
SO WHAT's THE DIFFERENCE:
Zener Breakdown:
Zener Breakdown occurs due to breaking of covalent bonds by the strong electric field set up in the depletion region by the reverse voltage.
It produces an extremely large number of electrons and holes which constitute the reverse saturation current (i.e. zener current) which value is limited by the external resistance in the circuit. It is independent of the applied voltage.
Avalanche Breakdown:
It occurs at higher reverse voltages when thermally generated electrons acquire sufficient energy to produce more carriers by collision.
(Note: All those topics defined here are gathered from web from different sources and most of the times definitions are being made to understand keeping that in mind different different sources are at one place being set to make you understand better. Well the definitions and notes are of their respective owners and sometimes it's mine creativity ;) ..
So What is Zener Breakdown?
The Zener effect is a type of electrical breakdown in a reverse biased p-n diode in which the electric field enables tunneling of electrons from the valence to the conduction band of a semiconductor, leading to a large number of free charge carriers, which suddenly increase the reverse current. Zener breakdown is employed in a Zener diode.
Avalanche Breakdown?
Avalanche breakdown is a phenomenon that can occur in both insulating and semiconducting materials. It is a form of electric current multiplication that can allow very large currents within materials which are otherwise good insulators. It is a type of electron avalanche. The avalanche process occurs when carriers in the transition region are accelerated by the electric field to energies sufficient to free electron-hole pairs via collisions with bound electrons.
SO WHAT's THE DIFFERENCE:
Zener Breakdown:
Zener Breakdown occurs due to breaking of covalent bonds by the strong electric field set up in the depletion region by the reverse voltage.
It produces an extremely large number of electrons and holes which constitute the reverse saturation current (i.e. zener current) which value is limited by the external resistance in the circuit. It is independent of the applied voltage.
Avalanche Breakdown:
It occurs at higher reverse voltages when thermally generated electrons acquire sufficient energy to produce more carriers by collision.
(Note: All those topics defined here are gathered from web from different sources and most of the times definitions are being made to understand keeping that in mind different different sources are at one place being set to make you understand better. Well the definitions and notes are of their respective owners and sometimes it's mine creativity ;) ..
EmoticonEmoticon