Diode Zener diode is a type of semiconductor diode which allows the flow of current only from the anode to the cathode, as in conventional diode prostowniczej, but in the opposite direction, when a certain potential difference on the electrodes of the element. Zener diodes are characterized by highly domieszkowanym connector PN. Typical LEDs silicone for a large reverse voltage experience a breakthrough, but the tension level, the opposite by which this occurs and the sharpness of this transition are not as well developed as the Zener. Strict control over the breakdown voltage - the voltage of the Zener diode, allows the use of these semiconductor elements as a voltage reference or voltage stabilizers. Led Zener diode can be the perfect solution for Your project.
Unusual phenomenon of electrical breakdown discovered by the American physicist Clarence Melvin Zener, helped to create a unique type of semiconductor device, which is led Zener diode. The effect of the Zener diode is a kind of electrical breakdown. There, in the diode with the connector PN, polarized in the direction zaporowym, when the electric field enables tunneling of electrons strip walencyjnego in the band of conductivity of the semiconductor, which leads to the formation of a large number of available speakers of minority languages who suddenly increase flowing through the element current is reversing.
In terms of the polarity of the LEDs in the direction zaporowym under relatively high tension, the area to impoverish connectors PN is expanding, which leads to generation of high electric fields at high power at the connector. A sufficiently strong electric field provide the electron tunneling in the region of the degradation of the semiconductor, which leads to generation of a large number of free charge carriers. This sudden generation of carriers sharply increases the reverse current and causes an increase in conductivity with a large bias in the characteristics And/V Zener. The effect of the Zener diode differs from avalanche breakdown. It is the electric field acceleration of electrons minorities in the region of the transition to an energy sufficient to release the couples electron-hole via collisions with bound electrons. The effects of Zener and avalanche can, but need not, współwystępować in the diode.
Normal diodes are not designed to work in the disaster area, while Zener diodes work reliably in this area. This unique property is ideal for a range of applications that make use of the fact that the breakdown of the Zener diode in the circuit there for a certain voltage for each model element. The typical application of this phenomenon is the use of LEDs of this type as a parallel voltage regulator. If such a diode is connected in series with a resistor will make the current about the value such that the voltage drop across the resistor that the voltage across the Zener diode will be equal to the voltage of the Zener element. In other applications, LEDs, Zener - protected from voltage surges. In order to limit the voltage at the input puts the device in parallel with the Zener diode - it's presence will make it so that the input voltage does not exceed never the Zener voltage of this element.