Turn-off characteristics of p-n-p-n devices

Abstract The turn-off characteristics of p-n-p-n devices are investigated and a general turn-off criterion is established. It is found that the voltage across center junction of a p-n-p-n device at the onset of turn-off is not zero as assumed by previous investigators, but the junction is forward biased. Experimental results of the gain and junction voltages at turn-off agree closely with those predicted theoretically.