A new base drive method for ultra fast, high voltage switching with darlingtons

This paper discribes a new base drive method which increases the switching speed and the safe operating area of bipolar transistors and darlingtons. The new base drive avoids the drawbacks of the well known cascode arrangement. The paper shows a model for understanding the ultra fast switching and the extension of the R.B.SOA as well as a praticai example of a bipolar darlington switch, able to turn-off 10 A–1000 V with a turn-off delay of 0, 4 μs and a collector current fall-time of less then 10 nanoseconds.