What is an IGBT transistor?
Insulated gate bipolar transistor or IGBT (abbreviated as Insulated gate bipolar transistor) is a power semiconductor and is primarily used as an electronic switch that is used in new devices for high efficiency and fast switching. This electrical switch is used in many modern appliances, including electric cars, trains, refrigerators, treadmills, air conditioners, and even stereo and amplifier systems. It is also used in making all kinds of inverters, welding transformers and UPS.
At high switching frequencies, a transistor is used to control the DC voltage level. As the frequency increases, the transistor no longer functions linearly and produces strong telecommunication noise with high power. For this reason, low power MOSFET element is used in high switching frequency. But as the power increases, its losses also increase. A new element has come to the market that has all the advantages of the above 2 parts and no longer has the disadvantages of BJT and POWER MOSFET. This new part is called IGBT. In recent years, due to its cheapness and advantages, this part has been used a lot.
The IGBT (Insulated Gate Bipolar Transistor) component is a new and completely industrial semiconductor that is made by combining 2 types of transistors, BJT and MOSFET. So that from the input point of view you see a MOSFET and from the output point of view a BJT.
BJT transistors and MOSFETs have characteristics that complement each other from some points of view. BJTs have lower conductive losses in the on state; while their switching time is longer, especially during shutdown; But MOSFETs are able to switch on and off much faster. Therefore, their conduction losses are higher.
The result is that IGBT is a transistor that has the advantages of BJT and MOSFET together, such as:
High input impedance like MOSFET, low voltage drop and loss like BJT, like BJT has a small on-state voltage.
The names of the bases are also chosen from the same names as before: G from MOSFET and C, E from BJT transistors. As a result, with this simple combination, you use a German that has high gate impedance and high voltage tolerance.
The switching speed of this type is limited, for example, 1KHz to 50KHz, which is generally between two types of BJT and MOSFET; And it is very sensitive because of its very high input impedance; And it is mostly used in induction furnaces to strengthen the voltage range. In general, these types of transistors are mostly used for starting high power elements.
The most important and almost the only efficiency of IGBT switching is high currents.
This post is written by kamalifard