Diode is usually regarded as a means of distributing electricity to one direction, but Zener diodes are made so that current can flow in the opposite direction if the applied voltage exceeds the limit "stress damage" (breakdown voltage) or "Zener voltage".
Normal diode will not allow electric current to flow through the opposite if supplied (reverse-biased) below breakdown voltage. If you exceed the limit of breakdown voltage, normal diode will be damaged because of too much electrical current that causes heat. But this process is reversible if done within limits. In the case of rationing-forward (in accordance with the direction of the arrow), this diode will provide voltage drop (voltage drop) of about 0.6 volts for silicon diodes used. Voltage drop depends on the type of diode used.
A Zener diode has almost the same properties with ordinary diodes, except that the equipment is damaged deliberately made with a greatly reduced tengangan, called Zener voltage. A Zener diode has a pn junction which has a heavy doping, which allows electrons to penetrate (tunnel) from the valence band p-type material into the conduction band n-type material. A Zener diode is supplied through the broken behavior will exhibit a controlled and will pass an electric current to keep the voltage drop in order to remain on the zener voltage. For example, a 3.2 volt zener diode voltage drop will show on the 3.2 volt supply if given back. However, because the current is not unlimited, so the zener diode is typically used to generate a reference voltage, or voltage stabilizer for small flow applications.
The breakdown voltage can be controlled quite accurately in the doping process. Tolerance of 0.05% can be achieved despite the most usual tolerance is 5% and 10%.
This effect was discovered by an American physicist, Clarence Melvin Zener.
Another mechanism that produces the same effect is the avalanche effect as in the avalanche diode. Both types of diodes are actually formed through the same process and both effects are present in both types of these diodes. In silicon diodes up to 5.6 volts, the zener effect is the main effect and this effect showed negative temperature coefficient. Above 5.6 volts, the avalanche effect becomes predominant and exhibits a positive temperature coefficient.
In the 5.6 volts zener diode, the two effects occur together and their temperature coefficients cancel each other. Thus, diodes 5.6 volts of choice in the application of temperature-sensitive.
the working principle of diode zener
diode zener are usually used extensively in electronic circuits. Its main function is to stabilize the voltage.
diode zener the time connected in parallel with a source voltage swings are installed so that the dole-back, a zener diode will act like a short circuit (short connection) when the voltage reaches the voltage diodes are damaged. Result, the voltage will be limited to a figure that has been previously known.