A new power transistor structure for improved switching performances

The performances of high voltage switching transistors in an inductive circuit are largely determined by the switching loss it incurred and also by the ruggedness to withstand reverse second breakdown. This paper presents an innovative emitter structure which has no adverse effect on static characteristics but provides at least three times improvement in switching loss and 10% improvement in RBSOA. It also has been demonstrated that RBSOA performance can further be enhanced drastically with the use of a multiple epitaxial layer collector structure. This coupled with the new emitter structure constitutes a new transistor structure that has low switching loss and rugged RBSOA performance.