Search results
Results from the WOW.Com Content Network
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 principle, avalanche breakdown only involves the passage of electrons and need not cause damage to the crystal. Avalanche diodes (commonly encountered as high voltage Zener diodes) are constructed to break down at a uniform voltage and to avoid current crowding during breakdown. These diodes can indefinitely sustain a moderate level of ...
The Zener diode exhibits an apparently similar effect in addition to Zener breakdown. Both effects are present in any such diode, but one usually dominates the other. Avalanche diodes are optimized for avalanche effect, so they exhibit small but significant voltage drop under breakdown conditions, unlike Zener diodes that always maintain a ...
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]
The effect is process dependent, but it can be minimized. Diodes may also be selected for low multistate noise. [10] A commercial example of an avalanche diode noise generator is the Agilent 346C that covers 10 MHz to 26.5 GHz. [11] Electronics portal
Severely overloaded Zener diodes in reverse bias shorting. A sufficiently high voltage causes avalanche breakdown of the Zener junction; that and a large current being passed through the diode causes extreme localised heating, melting the junction and metallisation and forming a silicon-aluminium alloy that shorts the terminals.
Avalanche diodes These are diodes that conduct in the reverse direction when the reverse bias voltage exceeds the breakdown voltage. These are electrically very similar to Zener diodes (and are often mistakenly called Zener diodes), but break down by a different mechanism: the avalanche effect. This occurs when the reverse electric field ...
The process can also be used to detect ionizing radiation by using the gas multiplication effect of the avalanche process. This is the ionisation mechanism of the Geiger–Müller tube and, to a limited extent, of the proportional counter [1] and is also used in spark chambers and other wire chambers.