Electrothermal failure safety of TIL GTO thyristors

The work presents the main dynamic characteristics testifying to the built-in electrothermal failure-safe features of 4 × 4 mm area TO-220-packed two-interdigitation-level (TIL) GTO thyristors. It is shown that 1) a fairly good and stable current balance between the interdigitated fingers is preserved during both the turn-off and turn-on; 2) the temperature rise in the structure of TIL GTO's is kept within safe limits under high-voltage/high-current conditions; 3) the final dimensions of the anode current crowding zone are large enough thus limiting the density of power dissipated during transient turn-off. Thanks to these self-protective features, the developed TIL GTO's possess the highest value of the peak interruptable anode current I
ATO
(60 A) ever reported in the open literature for this class of GTO's (identical device area and case) and could safely operate at high commutation frequencies under heavy load conditions.