Next Page After having known about various components, let us focus on another important component in the field of electronics, known as a Diode.
Light emitting diodes, LEDs are very widely used in today's electronics equipment and they are one of the major display technologies in use today. Diodes Incorporated is a leading global manufacturer and supplier of high-quality application specific standard products. Digi-Key is an authorized electronic components distributor with thousands of parts in-stock and ready for immediate shipment! Advanced Search X Advanced Stock Status: In Stock Diodes - Rectifiers - Arrays ( items).
Impurities are added to it to create a region on one side that contains negative charge carriers electronscalled an n-type semiconductorand a region on the other side that contains positive charge carriers holescalled a p-type semiconductor.
When the n-type and p-type materials are attached together, a momentary flow of electrons occur from the n to the p side resulting in a third region between the two where no charge carriers are present. This region is called the depletion region because there are no charge carriers neither electrons nor holes in it.
The boundary between these two regions, called a p—n junctionis where the action of the diode takes place. When a sufficiently higher electrical potential is applied to the P side the anode than to the N side the cathodeit allows electrons to flow through the depletion region from the N-type side to the P-type side.
The junction does not allow the flow of electrons in the opposite direction when the potential is applied in reverse, creating, in a sense, an electrical check valve.
Schottky diode Another type of junction diode, the Schottky diodeis formed from a metal—semiconductor junction rather than a p—n junction, which reduces capacitance and increases switching speed.
The shape of the curve is determined by the transport of charge carriers through the so-called depletion layer or depletion region that exists at the p—n junction between differing semiconductors. When a p—n junction is first created, conduction-band mobile electrons from the N- doped region diffuse into the P- doped region where there is a large population of holes vacant places for electrons with which the electrons "recombine".
When a mobile electron recombines with a hole, both hole and electron vanish, leaving behind an immobile positively charged donor dopant on the N side and negatively charged acceptor dopant on the P side.
The region around the p—n junction becomes depleted of charge carriers and thus behaves as an insulator. However, the width of the depletion region called the depletion width cannot grow without limit.
For each electron—hole pair recombination made, a positively charged dopant ion is left behind in the N-doped region, and a negatively charged dopant ion is created in the P-doped region.
As recombination proceeds and more ions are created, an increasing electric field develops through the depletion zone that acts to slow and then finally stop recombination. At this point, there is a "built-in" potential across the depletion zone.
A PN junction diode in forward bias mode, the depletion width decreases. Observe the different Quasi Fermi levels for conduction band and valence band in n and p regions red curves.
Reverse bias[ edit ] If an external voltage is placed across the diode with the same polarity as the built-in potential, the depletion zone continues to act as an insulator, preventing any significant electric current flow unless electron—hole pairs are actively being created in the junction by, for instance, light; see photodiode.
This is called the reverse bias phenomenon. Forward bias[ edit ] However, if the polarity of the external voltage opposes the built-in potential, recombination can once again proceed, resulting in a substantial electric current through the p—n junction i.
For silicon diodes, the built-in potential is approximately 0.
Thus, if an external voltage greater than and opposite to the built-in voltage is applied, a current will flow and the diode is said to be "turned on" as it has been given an external forward bias. The diode is commonly said to have a forward "threshold" voltage, above which it conducts and below which conduction stops.
However, this is only an approximation as the forward characteristic is smooth see I-V graph above. At very large reverse bias, beyond the peak inverse voltage or PIV, a process called reverse breakdown occurs that causes a large increase in current i.
The avalanche diode is deliberately designed for use in that manner. In the Zener diodethe 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 voltageand avalanche does not occur.
Both devices, however, do have a limit to the maximum current and power they can withstand in the clamped reverse-voltage region. Also, following the end of forward conduction in any diode, there is reverse current for a short time.Component Circuit Symbol Function of Component Transistor NPN A transistor amplifies current.
It can be used with other components to make an amplifier or switching. Diodes & Rectifiers are in stock with same-day shipping at Mouser Electronics from industry leading lausannecongress2018.com is an authorized distributor for many diode & rectifier manufacturers including Diodes Inc., Littelfuse, Microsemi, Nexperia, ON Semiconductor, STMicroelectronics, Taiwan Semiconductor, Vishay, & more.
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Each of these components has a specific function. Electronics Components Circuit Specialists carries a truly staggering selection of electronic parts and general supplies for your electronics projects.
If you belong to an educational institution you'll want to take a look at our educational electronic lab kitting service; simply submit a component list and we'll deliver your neatly pre. A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other.
A diode vacuum tube or thermionic diode is a vacuum tube with two electrodes, a heated cathode and a plate, in which electrons can flow in only one direction, from.