Bipolar and MOS Transistors: Emerging Partners for the 1980´s

The brief, but dynamic, history of power MOS transistors has been presented in this paper. Power MOS transistors have become accepted by "circuit design" engineers because of their performance advantages over bipolar transistors in certain applications. A comparison of MOS and bipolar transistors has been made. The strengths and weaknesses of each device type has been related to device structure. On the basis of this comparison, new applications for power MOS transistors in power supplies were presented. The comparison of the relative advantages of bipolar and MOS transistors suggested combining the device types to gain the advantages of each. The performance of the cascade, cascode, and the parallel configuration has been discussed. This performance is summarized in Figure 33. The development of new power semiconductor devices and power integrated circuits has not been discussed in this paper. Both of these areas promise to significantly impact the direction of power handling and conditioning technology. As new devices and integrated circuits become available to the design engineer, advancements in this area will continue.