{"id":128,"date":"2026-07-16T01:47:13","date_gmt":"2026-07-15T17:47:13","guid":{"rendered":"http:\/\/www.amico-in-affitto.com\/blog\/?p=128"},"modified":"2026-07-16T01:47:13","modified_gmt":"2026-07-15T17:47:13","slug":"how-does-an-igbt-work-4518-14c2c2","status":"publish","type":"post","link":"http:\/\/www.amico-in-affitto.com\/blog\/2026\/07\/16\/how-does-an-igbt-work-4518-14c2c2\/","title":{"rendered":"How does an IGBT work?"},"content":{"rendered":"

How does an IGBT work?<\/h2>\n

As a professional in the field of power semiconductors, especially as a supplier of thyristors, I am often asked about the intricacies of various semiconductor devices. One such device that has gained significant prominence in recent years is the Insulated Gate Bipolar Transistor, commonly known as IGBT. In this blog post, I will delve into the working principles of an IGBT, its applications, and its significance in the power electronics industry. Thyristor<\/a><\/p>\n

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Understanding the Basics of IGBT<\/h3>\n

To understand how an IGBT works, it’s essential to first grasp its basic structure. An IGBT is a three-terminal power semiconductor device that combines the advantages of both bipolar junction transistors (BJTs) and metal – oxide – semiconductor field – effect transistors (MOSFETs). The three terminals are the gate (G), the collector (C), and the emitter (E).<\/p>\n

The structure of an IGBT consists of four alternating layers of P and N semiconductor materials. It has a P – type substrate on the collector side, followed by an N – type drift region. Over this drift region, there are P – type and N – type regions near the emitter side. The gate terminal is insulated from the semiconductor by a thin layer of silicon dioxide, similar to a MOSFET.<\/p>\n

Working Principle<\/h3>\n

The operation of an IGBT can be divided into two main phases: the turn – on phase and the turn – off phase.<\/p>\n

Turn – on Phase<\/h4>\n

When a positive voltage is applied to the gate terminal with respect to the emitter, an electric field is created across the silicon dioxide layer. This electric field attracts electrons from the N – type region near the emitter towards the surface of the P – type region adjacent to the gate. As a result, an inversion layer is formed in the P – type region, which acts as a conductive channel between the N – type regions on either side.<\/p>\n

This conductive channel allows the flow of electrons from the emitter to the N – type drift region. At the same time, the positive voltage at the collector attracts these electrons. Additionally, holes are injected from the P – type substrate into the N – type drift region. These holes and electrons recombine in the drift region, creating a large current flow between the collector and the emitter. This process is similar to the conduction mechanism in a BJT, where minority carriers are injected into the base region to facilitate current flow.<\/p>\n

Turn – off Phase<\/h4>\n

To turn off the IGBT, the positive voltage at the gate is removed. When the gate voltage drops below a certain threshold value, the inversion layer in the P – type region near the emitter disappears. This cuts off the flow of electrons from the emitter to the drift region.<\/p>\n

However, the stored charge in the N – type drift region, mainly in the form of excess holes, needs to be removed. This is a relatively slow process compared to the turn – on process. The excess holes are recombined with electrons or swept out of the drift region by the electric field. Once the stored charge is removed, the current flow between the collector and the emitter stops, and the IGBT is turned off.<\/p>\n

Advantages of IGBTs<\/h3>\n

IGBTs offer several advantages over other power semiconductor devices, which have contributed to their widespread use in various applications.<\/p>\n

High Voltage and Current Capabilities<\/h4>\n

IGBTs can handle high voltages and currents, making them suitable for high – power applications such as electric vehicle (EV) drivetrains, industrial motor drives, and renewable energy systems. Their ability to withstand high voltages is due to the presence of the N – type drift region, which can support a high electric field without breakdown.<\/p>\n

Low Conduction Losses<\/h4>\n

Compared to MOSFETs, IGBTs have lower conduction losses at high – voltage and high – current levels. The injection of minority carriers in the drift region during conduction reduces the resistance of the device, resulting in lower power dissipation. This property makes IGBTs more efficient in high – power applications.<\/p>\n

Easy to Control<\/h4>\n

Similar to MOSFETs, IGBTs can be easily controlled by a voltage signal applied to the gate. This makes them compatible with modern control circuits and microcontrollers, allowing for precise control of power flow in various applications.<\/p>\n

Applications of IGBTs<\/h3>\n

IGBTs have found a wide range of applications in the power electronics industry due to their unique combination of high – power handling capabilities and easy controllability.<\/p>\n

Electric Vehicles<\/h4>\n

In electric vehicles, IGBTs play a crucial role in the motor drive system. They are used to convert the direct current (DC) from the battery into alternating current (AC) to drive the electric motor. The high – power handling capabilities and high efficiency of IGBTs are essential for providing the necessary power to the motor while ensuring optimal energy consumption.<\/p>\n

Renewable Energy Systems<\/h4>\n

IGBTs are also widely used in renewable energy systems such as solar photovoltaic (PV) inverters and wind turbine converters. In PV inverters, IGBTs are used to convert the DC power generated by the solar panels into AC power that can be fed into the grid. In wind turbine converters, they are used to control the power flow from the generator to the grid, ensuring stable and efficient operation.<\/p>\n

Industrial Motor Drives<\/h4>\n

In industrial applications, IGBT – based motor drives are used to control the speed and torque of electric motors. These drives offer precise control, high efficiency, and reduced power consumption compared to traditional motor control methods.<\/p>\n

Comparison with Thyristors<\/h3>\n

As a thyristor supplier, I often have customers asking about the differences between thyristors and IGBTs. While thyristors and IGBTs are both power semiconductor devices, they have some key differences in their working principles and applications.<\/p>\n

Working Principle<\/h4>\n

Thyristors are four – layer, three – terminal devices that operate based on a regenerative feedback mechanism. Once a thyristor is triggered, it remains in the conducting state until the current through it drops below a certain holding current value. In contrast, IGBTs can be turned on and off by controlling the gate voltage, allowing for more flexible operation.<\/p>\n

Applications<\/h4>\n

Thyristors are commonly used in high – power applications where a large amount of power needs to be controlled in a relatively simple way, such as in high – voltage direct – current (HVDC) transmission systems and some types of industrial heating applications. IGBTs, on the other hand, are more suitable for applications that require fast switching and precise control, such as motor drives and renewable energy systems.<\/p>\n

Conclusion<\/h3>\n

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In conclusion, the IGBT is a remarkable power semiconductor device that has revolutionized the power electronics industry. Its unique combination of high – power handling capabilities, low conduction losses, and easy controllability has made it the device of choice for a wide range of applications.<\/p>\n

Thermistor<\/a> As a supplier of thyristors, I understand the importance of providing our customers with high – quality power semiconductor solutions. Whether you are looking for thyristors or interested in exploring the potential of IGBTs for your application, I encourage you to reach out to us. Our team of experts is ready to discuss your requirements and provide you with the best possible solutions.<\/p>\n

References<\/h3>\n