NEW ASPECTS OF SECOND BREAKDOWN IN TRANSISTORS

IT HAS BEEN FOUND THAT THE NATURE OF SECOND BREAKDOWN IS MORE BASIC THAN HERETOFORE RECOGNIZED. The study has revealed that second breakdown is exhibited in both collector-tobase and emitter-to-base diodes of the transistors as well as voltage regulator diodes. The only restriction on this observation is that the applied diode voltage must be in excess of the sustaining second breakdown voltage. From the nature of the observed thermal resistance characteristics of transistors, it has been assumed that second breakdown is thermal in nature. On this basis an expression has been developed which leads to a first order prediction of the open base breakdown current. Author