Comparison of RBSOA of ESTs with IGBTs and MCTs

The reverse biased safe operating area (RBSOA), at snubberless inductive load state, of 600 V and 2500 V emitter switched thyristors (ESTs) has been analyzed numerically and experimentally for the first time and compared to those for the IGBT and MCT. The dependence of the RBSOA upon the P base resistance (R/sub b/) in the main thyristor structure of the EST, which affects the triggering and holding currents of the device, has also been investigated. Two types of destructive failure mechanisms have been identified. One is due to the voltage-induced avalanche multiplication, the other is attributed to the current-induced latch-up of the parasitic thyristor. Physical analysis of the RBSOA's configuration is also discussed.