In most electronic circuits, the power diode acts as a key component in maintaining the flow of the current between two terminals. It acts as a gate, whose primary function is to control the unidirectional current flow without any fail. Usually, power diodes are often associated with high power applications where a huge amount of current needs to flow between the terminals. The voltage across the points is maintained at high level with the internal diode resistance being marked at lower values. These diodes do not have enough switching power, which is why the current’s direction cannot be reversed during the operation.
Owing to the vast applications, several types of power diode modules have been introduced in the microelectronics market. From Zener to laser and LEDs, each module is designed to function in a specific manner. If you are designing any project related to electronics, knowing about these modules is imperative. Considering this, we have discussed the most used power diode categories in the industry.
Rectifier Diodes
In several electronics circuit, the main AC power supply needs to be converted into DC current before feeding the same to other elements. This task is usually done by the rectifier power diode modules. They are made of special PN junctions that can block the alternating voltage cycles by switching the terminals rapidly. It is classified into two types, half-wave and full-wave rectifier diodes. In half-wave diodes, the positive part of the AC voltage is allowed to pass through and appear at the output while the negative part is canceled. On the contrary, in the full-wave rectifier, two diodes are used with opposite terminal arrangements. During a single AC cycle, one diode remains operational while the other is switched off due to which the entire wave cycle appears at the output in the form of DC current.
Light Emitting Diodes
We all know what light emitting diodes or LEDs are. This diode module is made of special semiconductors like indium gallium nitride or aluminum gallium arsenide. When electric current is produced across the terminals, the electrons and holes in the semiconductors are excited and they jump to the higher energy levels. Since the electrons are unstable at these levels, they soon jump to their original state by releasing their energy in the form of electromagnetic waves. These EM waves have the wavelength within the visible spectrum, which is why you can see the diodes emitting different colors when the circuit is switched on. The color will depend on the type of semiconductor material used, like red and infrared LEDs have aluminum gallium arsenide semiconductor while yellow and green LEDs are made from gallium phosphide.
Zener Diodes
Also known as shunt diodes, Zener is a popular power diode module used to regulate the voltage output across smaller loads connected between the output terminals. It functions just like a regular diode in the forward biasing mode, i.e. when the diode terminals are connected to the opposite voltage terminals. However, in the reverse biasing mode, the high voltage applied across the terminals allows the current to flow through the semiconductor material. As the voltage increases, the current generated also increases and soon reaches the maximum level as determined by the series resistor connected to the diode. Once it attains the maximum level, the current flow within the Zener diode remains consistent even if you increase the load voltage across its terminals. It is to note here that Zener diodes are heavily doped to tolerate avalanche breakdown without suffering from internal damage.
Laser diodes
As the name implies, laser diode is a special diode module used in various purposes, including fiber optic data transmission, manufacturing, medical procedures, and many more. It produces coherent radiations with frequency within the visible or infrared regions of the entire electromagnetic spectrum. Several types of laser diodes are used in the industry, including quantum well laser diode, double heterostructure laser diode, and vertical cavity surface-emitting laser diode. Even though the operating principles of this module is almost similar to that of the LEDs, laser diodes do not need such high operational power, which is why these are used in areas where the circuit load is small. Furthermore, the light waves generated are of higher efficiency and the intensity can be altered by varying the input voltage.
Conclusion
In this article, we have discussed the major types of power diode modules used in the semiconductor industry. Before you use a specific type in your electromagnetic project, it is important to learn more about their IV characteristics in both forward and reverse bias functional modes. Furthermore, ensure you apply the right voltage across the terminals to prevent breakdowns at the depletion region.
