Evaluation of Si and SiC SGTOs for High Action Army Applications

The U. S. Army Research Laboratory (ARL) has been exploring silicon and silicon carbide Super gate turn-off thyristors (SGTOs) for high power pulse switching required by Army survivability and lethality applications. Silicon SGTOs (3.5 cm²) were pulsed at 5 kA with a half-sine current waveform measuring 1 ms at the base. The recovery time, or T_q, of the devices was evaluated from the point at which the main current pulse fell to zero. Using a driver designed to provide both turn-on and turn-off signals, the T_q was reduced to 10 mus. Smaller silicon carbide SGTOs (0.16 cm²) were similarly evaluated for wide-pulse performance. They were switched several times at a peak current above 300 A, with an unassisted T_q time of 30 mus. This paper provides details of the aforementioned pulse switching, as well as a description of continuing evaluations involving parallel devices and larger test beds.