CRYOGENIC OPERATION OF ASYMMETRIC FIELD CONTROLLED THYRISTORS

Detailed measurements and modeling of 500 V asymmetric field controlle d thyristor characteristics in the 300-77 K temperature range are pres ented for the first time. When the temperature is reduced from 300 to 77 K, it has been found that: the forward voltage drop increases by ab out 40%; the breakdown voltage reduces by 20%; the blocking gain remai ns essentially constant; the turn-off time reduces by 10 x and the gat e charge withdrawn via the gate current flow during turn-off reduces b y 95 x. The forward voltage drop versus turn-off time trade-off curve obtained by temperature reduction is found to be much superior to that obtained by electron radiation.