Switching behavior and current handling performance of MCT:IGBT cell ensembles

The dynamic characteristics of large MCT (MOS controlled thyristor) ensembles have been improved by integrating IGBT (insulated-gated bipolar transistor) cells for turn-on and different schemes of cathode and anode shorting for turn-off. Such MCT-IGBT ensembles with integrated shorts are able to turn off 4 A (240 A-cm/sup -2/) at 1000 V in typically 1.5 mu s in the inductive clamped mode. The authors report on the effectiveness of these different approaches and their parasitic influence on the turn-on characteristic and the maximum turn-off current capability. The implementation of permanent cathode shorts has lead to an increase of the maximum turn-off current of large MCT ensembles, whereas anode shorting leads to faster turn-off and lower tail currents. A careful design of the IGBT turn-on cell and placement is required for proper MOS turn-on even at low anode voltages.<
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