13580742170

HuiXin Electronic

HuiXin Electronic2017/9/6 16:20:00

Huixin Explains the Breakdown on Zener Diode

  Introduction

  A normal P-N junction diode is usually fabricated by adjusting the P-type and N-type semiconductors on a single semiconductor crystal. The characteristics of a junction diode demonstrate that it is designed largely for operating in the forward direction. Applying a large amount of forward bias causes greater forward current with a small value of forward voltage.

  However, reverse biasing the diode do not cause conduction of current till high values of reverse voltage are reached. If the reverse voltage is large enough, breakdown occurs and a reverse current starts to flow. Ordinary Junction diodes are generally damaged when this breakdown occurs. The flow of current in zener diodes is controlled by the minority charge carriers under the reverse bias condition, so they can also be referred to as break down diodes.

Huixin Explains the Breakdown on Zener Diode

  Avalanche Breakdown

  It is predominant above approximately 5.5 volts. This mechanism is also referred to as impact ionisation or avalanche multiplication. For reverse conduction it is necessary to visualise the phenomenon of avalanche breakdown. This process begins when a large negative bias is applied to the PN junction, sufficient energy is imparted to thermally generated minority charge carriers in the semiconductors.

  As a result the free carriers acquire required kinetic energy to break the covalent bonds and create an electric field through collisions with crystal particles. The charge carriers created in collision contribute to the reverse current, well beyond the normal reverse saturation current and may also possess enough energy to participate through collisions, creating an additional electric field and the avalanche effect by impact ionization, once a sufficiently high reverse bias is provided this process of conduction takes place very much like an avalanche: a single electron can ionise several others.

Huixin Explains the Breakdown on Zener Diode

  Zener Breakdown

  It is predominant below approximately 5.5 volts. This mechanism is also referred to as a high field emission mechanism. The phenomenon of zener breakdown is related to the concept of avalanche breakdown. Zener breakdown is achieved by heavily doped regions in the neighbourhood of ohmic contact.

  It is the second method of disturbing the covalent bonds of the crystal atoms and increasing the reverse bias zener diode current, to be sustained at a much lower specific voltage than normal diode. The reverse bias voltage known as zener voltage, where this mechanism occurs is determined by the diode doping concentration and it occurs when the depletion layer field width is sufficiently enough to disrupting the covalent bonds and cause number of free charge carriers due to electric field generation to swell.


HuiXin Electronic

Huixin Electronic Great wisdom, a core is infinite, to build the best semiconductor device industry!

Contacnt Us

Address:7/F,Building 10,Tiansheng Industrial Park,No.1 Luochongfang Industrial 2nd Road,Wanjiang Street, Dongguan City,Guangdong Province

Tel:13580742170 / 0769-22857832

Focus Us

2010-2019 © HuiXin Electronic All Rights Reserved Tel:0769-22857832 Fax:0769-22857361