What is an IGBT transistor?

In parallel with the study of the properties of semiconductorsThere was also a perfection of the technology of manufacturing devices based on them. Gradually appeared all the new elements, with good performance characteristics. The first IGBT-transistor appeared in 1985 and combined the unique properties of bipolar and field structures. As it turned out, these two types of semiconductor devices known at the time can well "get along" together. They created a structure that became innovative and gradually gained immense popularity among the developers of electronic circuits. The very abbreviation IGBT (Insulated Gate Bipolar Transistors) indicates the creation of a hybrid circuit based on bipolar and field effect transistors. At the same time, the ability to work with large currents in power circuits of the same structure was combined with a high input resistance of the other.

The modern IGBT-transistor differs from itspredecessor. The fact is that the technology of their production has been gradually improved. Since the appearance of the first element with this structure, its main parameters have changed for the better:

• The commutated voltage increased from 1000V to 4500V.This allowed the use of power modules when working in high voltage circuits. Discrete elements and modules have become more reliable in working with inductance in the power circuit and more protected from impulse noise.
• Switching current for discrete elements has grownup to 600A in discrete and up to 1800A in modular design. This allowed switching large current circuits and using an IGBT transistor to work with motors, heaters, various industrial installations, etc.
• The direct voltage drop in the open state dropped to 1V. This allowed to reduce the area of ​​heat sinks and simultaneously reduce the risk of failure from thermal breakdown.
• Switching frequency in modern devicesreaches 75 Hz, which makes it possible to use them in innovative control circuits for the electric drive. In particular, they are successfully used in frequency converters. Such devices are equipped with a bus controller, which operates in a "bundle" with the module, the main element in which is an IGBT transistor. Frequency converters gradually replace traditional electric drive control circuits.
• The speed of the device also increased greatly.Modern IGBT transistors have di / dt = 200μs. This refers to the time taken to turn on / off. Compared with the first samples, the performance increased fivefold. Increasing this parameter affects the possible switched frequency, which is important when working with devices that implement the principle of control.

Electronic circuits were also improved,which controlled the IGBT-transistor. The main requirements that were imposed on them - is to ensure a safe and reliable switching device. They must take into account all the weak points of the transistor, in particular, its "fear" of overstress and static electricity.