200 kHz, High Power, on Board Converter

Recently, the large computer system received a remarkable high packing density rating by using LSI and VLSI for its logic device. To keep pace with this miniaturization, the requirement for the power supply unit; reducing its size and raising its efficiency, is growing strong. We have consistently adopted a switching mode power supply to satisfy this requirement, and have tried to get a higher switching frequency. Switching frequency was 4 kHz to 20 kHz in the 1970´s, 50 kHz to 100 kHz in the 1980´s. And recently we developed 200 kHz, 200 W - 1.5 kW, dc to dc converter by using high speed, high voltage power MOS FETs and high density packing technology. This paper describes some features of this converter and the results of the development.