Improved recovery of fast power diodes with self-adjusting p emitter efficiency

A fast p-n-n/sup +/ power rectifier, which shows a significantly improved recovery behavior, is discussed. The p layer of this diode consists of a p/sup +/ region of high injection efficiency and a densely interspersed p region of low injection efficiency. The lateral distances are chosen in such a manner that the high efficiency of the p/sup +/ region becomes effective at high currents only, whereas, up to the normal operative forward current, the p emitter efficiency is small. By commutation, this results in a strong reduction of the peak reverse current and a significantly softer reverse current decay compared to standard diodes designed for the same blocking and forward voltages.<
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