Switching Diodes

What are Diodes?

A diode is a very simple device that provides the foundation of some of the most utilized technology in existence. A diode is essentially a device that allows electrical current to pass in one direction but not in the other. This is described as an asymmetric transfer characteristic. Diode can be made out of semiconductors, vacuum tubes and other components.

In a diode, the direction in which current can flow is described as the forward direction. The direction in which current is completely blocked is called the reverse direction. This complete resistance to flow in a specific direction allows diodes to be used for what is called rectification, the changing of AC current into DC current.

The description above describes the simplest type of diode. Other types of diode have more sophisticated functions. For example, there are some diodes available – made out of semiconductors – that will only start functioning when a certain voltage is achieved.

Diodes can be customized by using different materials and different manufacturing techniques to produce exactly the characteristics needed for a specific application.

As is the case with most electrical components, there is an ideal sort of diode that is conceivable. That diode would allow an infinite amount of current to be passed through it in one direction and prevent an infinite amount of current from being passed through in the other direction. In reality, this is typically not an achievable goal. Whenever an ideal diode or an ideal world are being discussed, however, diodes would let any amount of electrical energy pass through them in the forward direction and would resist any electricity passing through them in their reverse direction.

In everyday life, diodes are commonly used in a huge number of different applications. Light emitting diodes, for example, have largely replaced incandescent bulbs in lighting displays, traffic signals, car lighting and so forth. These styles are able to produce a tremendous amount of light with very little wattage, particularly when compared with inefficient incandescent lighting.

Diodes are also used in very advanced applications. For example, lasers can be generated with specific diodes. Whether diodes are buried deep in the inner workings of an electronic device or are providing the light that allows you to drive in the darkest nights, they are vital electronic components and one of the most ubiquitous, affordable and useful applications of semiconductor materials in the world.

Diodes are very basic electronic components, so they are manufactured by a wide variety of different companies. They are also very inexpensive, allowing them to be purchased and utilized freely any electronic devices without significantly driving the price up. In this way, diodes not only save power, they also allow very sophisticated devices to be manufactured at a very low cost compared to what would have been required not too far in the past.

What is a Switching Diode?

A switching diode is one that can change its forward or backward characteristics. These are commonly used in high frequency applications. In most regards, they are the same as a rectifier. They are oftentimes used, however, in the role of a switch, hence the name.

A switching diode is typically manufactured out of semiconductor materials. There are many different configurations of these devices available, each of which has a specific area in which it is ideally suited for usage. Some, for example, have dual cathodes, dual anodes and so forth. They can also be hooked up in various configurations to accommodate different needs.

How does a Switching Diode Work?

Switching diodes work by responding to a specific voltage. When a specific voltage is reached, the switching diode reverses its forward and reverse directions, allowing the passage of voltage through a circuit. In this regard, they function exactly the same way as a switch would, allowing the controlled energizing of a given circuit in a system.

Switching diodes are used in a wide variety of different applications. In any application where the energizing of a circuit needs to be controlled automatically, this can be accomplished by using a switching diode, providing it with the correct voltage under the right circumstances and, because of that, allowing a switch to be energized as needed.

Switching diodes need to be operated within certain voltages, certain currents and within a certain temperature range to function properly. If, for example, the maximum operating voltage of a switching diode is exceeded, it will generally stop allowing current to pass through in any direction, which can render the device useless.

While the ideal diode would be able to handle infinite current or voltage in either direction – passing it through in one direction and obstructing it in the other – anything involving a switching diode has to be calculated realistically, and that means determining what the maximum voltages are and how they will affect how the switching diode works. If the maximums are exceeded, switching diodes do not work at all.

Who Produces Switching Diodes?

Switching diodes are basic components, so they are produced by a great many different manufacturers. Here’s a list of some of the different manufacturers that produce these diodes.


A company located in Houston Texas that produces a wide variety of different switching diodes.

Fairchild Semiconductor

This semiconductor producer is located in San Jose, California, and produces a wide variety of switching diodes.


This company maintains a large catalog of electrical components, including switching diodes and many other products used to engineer electrical devices.


NXP Semiconductors has offices located all over the world and produces a wide variety of products utilized in the electronics industry.

ON Semiconductor

ON Semiconductor produces, among many other semiconductor products, switching diodes.


In addition to producing a wide range of consumer products, Panasonic also produces components, including switching diodes.

Renesas Electronics

With a US headquarters located in Santa Clara, California, Renesas Electronics offers many different products for designing and building electronic devices, including switching diodes.


ROHM is another large, globally present manufacturer of semiconductor products, including switching diodes and many others.


Vishay is another major manufacturer of switching diodes.

What types of configurations are available?


Switching diodes can be arranged in linear arrays and in two-dimensional arrays for various purposes.

Common Anode

This is a common configuration for switching diodes. It is commonly used in various types of receivers and measuring tools. In this configuration, two diodes share a common anode.

Common Cathode

This is another arrangement of switching diodes that is oftentimes utilized in measuring devices and receivers. The opposite of above, in this configuration, the diodes share a common cathode.


A dual configuration is oftentimes employed in applications where very high-speed switching is a necessity. This configuration involves utilizing two diodes in conjunction with one another.

Dual Anode

The dual anode design is another configuration that is commonly employed in ultrahigh switching capacities. The dual anode accommodates this.

Dual Common Anode

Like dual anode and dual configurations, the dual common anode configuration is one that is ideally suited for ultrahigh switching applications.

Dual Parallel

Connecting dual switching diodes in parallel is a fairly common application of these devices. It is oftentimes applied in applications where very fast switching needs to be done, when it can help to reduce heat and other issues. Parallel connections also maintain the same voltage across both diodes.

Dual Series

Switching diodes may also be configured in a series arrangement, which is the preferred method when parallel circuits are not desirable. This is utilized when the total voltage needs to be distributed over more than one diode.


This describes a circuit where a single switching diode is used on its own. This is, of course, a very common configuration.


This configuration is utilized in many fast switching and high-tech applications. The utilization of additional components is particularly useful in some very demanding applications.

Triple Parallel

This is a version of a triple switching diode configuration that involves a parallel circuit. This can make it possible to create a very fast circuit.

What is the Maximum Forward Current?

The maximum forward current in the switching diode is quite simply the maximum amount of current that that diode can handle before it breaks down. In addition to potentially causing trouble with the component in terms of damaging it, going over the maximum forward current has additional dangers, as well. The principal consideration with this limitation is heat. If the amount of heat that the diode can handle is exceeded, the part will inevitably fail.

When the forward current limit is exceeded, the diode will no longer allow current to pass through it. This will effectively switch the circuit off, which may render the device to which the diode is attached completely inoperable. In an ideal situation, the amount of current that’s allowed to pass through it in the forward direction would be infinite. This is one of the specifications that needs to be considered whenever purchasing a switching diode.

What is the Maximum Reverse Voltage?

The maximum reverse voltage for a switching diode is the peak amount of voltage that the diode can handle in a reverse bias mode. This assumes that the voltage is applied continuously. In a perfect diode, this maximum reverse voltage would be infinite. In reality, of course, no electrical component can handle an infinite amount of voltage, so the ceiling limit on how much voltage a diode can handle must always be considered when selecting a component.

What is the Maximum Forward Voltage?

The maximum forward voltage is the highest amount of voltage that can be passed through the diode in a forward direction. If this limit is exceeded, the diode is likely to stop functioning at all and, of course, there is a significant danger that any circuitry to which the diode is connected could be damaged by overheating and other problems. This is another very important specification that engineers take into consideration when they are deciding upon what parts to use in a project.

What Does PIN Count Define?

PIN count refers to the number of pins on an integrated circuit device. A PIN diode is a specific type of diode that is made out of semiconducting materials. The PIN diode allows the passage of electrons when one end of the diode is filled with electrons.

PIN diodes take their name from the arrangement of the different semiconductor types on the diode itself. There are three regions, p-type, i-type and n-type. From this, the name PIN is derived.

What Does Maximum Diode Capacitance Define?

Maximum diode capacitance is the maximum amount of capacitance that a diodes can achieve given the application of the voltage. It is most commonly used in reference to Varicap diodes, which are diodes that are able to bury their capacitance under certain circumstances. These are oftentimes found used in radio receivers, television sets and other electronic devices.

What Does the Maximum Operating Temperature define?

Semiconductor devices are prone to failure if they are overheated. The operating temperature of a diode will have a maximum level and cannot be exceeded. If this level is exceeded, it is likely that the device will fail.

Various cooling systems are generally used on semiconductor devices to provide this cooling. One of the simplest examples of this are the cooling fans that are used in computers to ensure that the components on the motherboard do not exceed the maximum operating temperature. Like all semiconductor devices, diodes do have a maximum temperature like they can handle before they will stop functioning as intended.

What Does the Minimum Operating Temperature Define?
Just as there is a maximum operating temperature for a switching diode, there is a minimum operating picture, as well. Sometimes, this is specified as a separate number unto itself and, in other cases, this will be expressed as the bottom end of the range of operating temperatures that are recommended for the device.
In situations where it is likely to be a problem for electronic devices, heating elements are oftentimes added to ensure that everything is operating within the approved parameters.

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