Power MOS Technology Invades Telecom

The steady march of semiconductor device technology is most publicized in the high density, low-voltage digital area. Another area, power control and power conversion technology, is moving forward as rapidly, but in a less visible fashion. This paper discusses the progress being made in power MOS device and circuit technology and its impact on power control. The development of new devices and integrated circuits is emphasized. These devices include depletion-mode MOSPOWER transistors, MOS-gated 4-layer devices, and low on-resistance MOSPOWER transistors. Specific device applications in power conversion circuits are covered. Integrated circuits for use in Telecommunications Power Conversion systems are also discussed. One new I.C., a one-watt 48-to-5 volt monolithic S.M.P.S., is presented as an example of the types of circuits that are becoming available.