Working principle | Semiconductor |
---|---|
Invented | 1959 |
Electronic symbol | |
IGBT schematic symbol |
An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily forming an electronic switch. It was developed to combine high efficiency with fast switching. It consists of four alternating layers (NPNP)[1][2][3][4][5] that are controlled by a metal–oxide–semiconductor (MOS) gate structure.
Although the structure of the IGBT is topologically similar to a thyristor with a "MOS" gate (MOS-gate thyristor), the thyristor action is completely suppressed, and only the transistor action is permitted in the entire device operation range. It is used in switching power supplies in high-power applications: variable-frequency drives (VFDs) for motor control in electric cars, trains, variable-speed refrigerators, and air conditioners, as well as lamp ballasts, arc-welding machines, uninterruptible power supply systems (UPS), and induction stoves.
Since it is designed to turn on and off rapidly, the IGBT can synthesize complex waveforms with pulse-width modulation and low-pass filters, thus it is also used in switching amplifiers in sound systems and industrial control systems. In switching applications modern devices feature pulse repetition rates well into the ultrasonic-range frequencies, which are at least ten times higher than audio frequencies handled by the device when used as an analog audio amplifier. As of 2010[update], the IGBT was the second most widely used power transistor, after the power MOSFET.[citation needed]
Device characteristic | Power BJT | Power MOSFET | IGBT |
---|---|---|---|
Voltage rating | High <1 kV | High <1 kV | Very high >1 kV |
Current rating | High <500 A | Low <200 A | High >500 A |
Input drive | Current ratio hFE ~ 20–200 |
Voltage VGS ~ 3–10 V |
Voltage VGE ~ 4–8 V |
Input impedance | Low | High | High |
Output impedance | Low | Medium | Low |
Switching speed | Slow (μs) | Fast (ns) | Medium |
Cost | Low | Medium | High |
{{cite journal}}
: CS1 maint: DOI inactive as of August 2024 (link)