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Useful information about Schottky diodes
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What was a Schottky diode?
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How do the diodes work?
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What are the areas of application of the diode with metal-semiconductor junction?
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What was the relevant purchase criteria?
What was a Schottky diode?
The Schottky diode is a diode with a metal-semiconductor junction, which has certain advantages due to its structure: Just like diodes with pn junction or semiconductor-semiconductor junction, Schottky diodes have a blocking function, which is achieved by a generated potential barrier, also called a Schottky barrier. verfügen Schottky-Dioden über eine sperrende Funktion, die durch eine erzeugte Potentialbarriere, auch Schottky-Barriere genannt, erzielt wird. Unlike pn diodes, the Schottky diode has several other advantages: Due to the materials used, it has a low forward voltage drop, a minimum power loss and short reverse delay times. These are in the range of a few nanoseconds with good diodes. Like their counterparts, they can be used as rectifiers for this purpose. By the way, the effect and the diode are named after physicist Walter Schottky, whereby the component is also named Hot-Carrier.
How do the diodes work?
The Schottky diodes operate in the same way as normal semiconductor semiconductor diodes, replacing a semiconductor with a metal: The metal-semiconductor contact creates a space charge zone that allows the current to flow in forward direction from a certain voltage, but at the same time stops in the opposite direction of blocking.
The materials consist of a (noble) metal layer such as chrome or platinum and an n-doped semiconductor layer, whereby the semiconductor consists mostly of silicon, for larger blocking voltages also of a silicon compound or gallium arsenide. The direction of passage or blocking is determined by the respective circuit of the anode with the metal layer and cathode with the n-doped layer and the charge with electrons.
What are the areas of application of the diode with metal-semiconductor junction?
Due to the fast switching and the short delay time, the diodes with metal-semiconductor junction can be used for a variety of applications. For example, they are better than pn diodes for high-frequency applications such as microwave ovens. Here they can be used as switching diodes or as rectifiers. Due to the low voltage drop, the electrical components can also be used as a protective element for transistors. Finally, they can be used in any area where a fuse is needed to prevent the flow of electricity or to regulate the current. This can be the case with both charging and power supplies. The latter show that the Schottky diodes are used in almost every device.
What was the relevant purchase criteria?
Conrad's range consists of a large number of different Schottky components, which offer you the right solution for every problem. When selecting the component, you should observe the following criteria:
Forward/reverse voltage and reverse current: The most important considerations naturally concern performance-related data. The questions about how high the forward voltage is or what voltage the Schottky component can block before it is damaged are elementary here. The forward voltage must be selected in such a way that current can flow at all. In the case of reverse voltage, however, it must be ensured that the diode can also cope with the voltages that arise without exceeding the breakdown voltage. As soon as the breakdown voltage exceeds a certain value, the reverse current increases and destroys the component. The reverse current indicator indicates how much current flows through the diode when operated in reverse direction. If this is too high, damage will occur. The data on this are different and can be found on the package.
Housing : the housing is important to protect it from environmental influences, but also to ensure adequate heat regulation and proper installation. Even though there is no standard for the housings internationally and individual manufacturers use their own housing forms, there are some standards: One of the most common for diodes is the DO format. DO stands for diode outline and describes a housing in the form of a cylinder at the ends of which are anode and cathode. With this, the diode can be attached precisely and space-saving. The arrangement of the connections, which in turn have an influence on the configuration of the electrical component, also depends on the selection of the housing.
Configuration : the configuration or arrangement of connections is particularly important for diode arrays. In this case, you should pay particular attention to whether the connections also match the later application possibilities and whether the correct number of connections is available. Special attention must also be paid to the arrangement and number of anode(s) and cathode(s) so that the diodes can be installed in the appropriate direction later on.
Schottky diodes not only offer a wide range of applications, but can also be flexibly adapted to different challenges with different power variants. The possibilities of use are further extended by the different housings and configurations, with which even more specific applications can be operated. With the purchase criteria described here, you will find the right diode for solving all pending tasks in our online shop.