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The Zener diode is therefore well suited for applications such as the generation of a reference voltage (e.g. for an amplifier stage), or as a voltage stabilizer for low-current applications. [ 2 ] Another mechanism that produces a similar effect is the avalanche effect as in the avalanche diode . [ 2 ]
In electronics, the Zener effect (employed most notably in the appropriately named Zener diode) is a type of electrical breakdown, discovered by Clarence Melvin Zener. It occurs in a reverse biased p-n diode when the electric field enables tunneling of electrons from the valence to the conduction band of a semiconductor , leading to numerous ...
In the Zener diode, the concept of PIV is not applicable. A Zener diode contains a heavily doped p–n junction allowing electrons to tunnel from the valence band of the p-type material to the conduction band of the n-type material, such that the reverse voltage is "clamped" to a known value (called the Zener voltage), and avalanche does not ...
A p-doped semiconductor (that is, one where impurities such as Boron are introduced into its crystal lattice) is relatively conductive. The same is true of an n-doped semiconductor, but the junction between them - the boundary where the p-doped and n-doped semiconductor materials meet - can become depleted of charge carriers such as electrons ...
Since the forward voltage of a diode is small, this kind of voltage regulator is only suitable for low voltage regulated output. When higher voltage output is needed, a zener diode or series of zener diodes may be employed. Zener diode regulators make use of the zener diode's fixed reverse voltage, which can be quite large.
This circuit mirrors the previous gate: the diodes are reversed so that each input connects to the cathode of a diode and all anodes are connected together to the output, which has a pull-up resistor. If any input is low, its diode will be forward-biased and will conduct current, and thus pull the output voltage low [c].
For example, the voltage of C 4 in the example would be at most 2U s - 4U f since there are 4 diodes between its positive terminal and the source. The total output voltage would be U(C 2) + U(C 4) = (2U s - 2U f) + (2U s - 4U f) = 4U s - 6U f. In a cascade with n stages of two diodes and two capacitors, the output voltage is equal to 2n U s - n ...
Here, the load current I R2 is supplied by the transistor whose base is now connected to the Zener diode. Thus the transistor's base current (I B) forms the load current for the Zener diode and is much smaller than the current through R 2. This regulator is classified as "series" because the regulating element, viz., the transistor, appears in ...