Device Description
An IGCT is a special type of thyristor similar to a GTO. They can be turned on and off by a gate signal, have lower conduction loss as compared to GTOs, and withstand higher rates of voltage rise (dv/dt), such that no snubber is required for most applications.
The structure of an IGCT is very similar to a GTO thyristor. In an IGCT, the gate turn off current is greater than the anode current. This results in a complete elimination of minority carrier injection from the lower PN junction and faster turn off times. The main difference is a reduction in cell size, plus a much more substantial gate connection with much lower inductance in the gate drive circuit and drive circuit connection. The very high gate currents plus fast dI/dt rise of the gate current means that regular wires can not be used to connect the gate drive to the IGCT. The drive circuit PCB is integrated into the package of the device. The drive circuit surrounds the device and a large circular conductor attaching to the edge of the IGCT die is used. The large contact area and short distance reduces both the inductance and resistance of the connection.
The IGCT's much faster turn-off times compared to the GTO's allows them to operate at higher frequencies—up to several of kHz for very short periods of time. However, because of high switching losses, typical operating frequency up to 500 Hz.
Read more about this topic: Integrated Gate-commutated Thyristor
Famous quotes containing the words device and/or description:
“UG [universal grammar] may be regarded as a characterization of the genetically determined language faculty. One may think of this faculty as a ‘language acquisition device,’ an innate component of the human mind that yields a particular language through interaction with present experience, a device that converts experience into a system of knowledge attained: knowledge of one or another language.”
—Noam Chomsky (b. 1928)
“Whose are the truly labored sentences? From the weak and flimsy periods of the politician and literary man, we are glad to turn even to the description of work, the simple record of the month’s labor in the farmer’s almanac, to restore our tone and spirits.”
—Henry David Thoreau (1817–1862)