The static induction thyristor (SIT, SITh) is a thyristor with a buried gate structure in which the gate electrodes are placed in n-base region. Since they are normally on-state, gate electrodes must be negatively or anode biased to hold off-state.[1] It has low noise, low distortion, high audio frequency power capability. The turn-on and turn-off times are very short, typically 0.25 microseconds.[2][3][4]