Autonomous control technique for high-performance switches

A method for creating high-performance switch modules from power transistors and simple control circuits is presented. The method is based on switching function principles by which any type of switch can be represented by an ideal switch in combination with basic logic elements. These high-performance modules can be configured to emulate diodes, thyristors, special resonant devices, or nearly any other switch type. The control is autonomous-it depends on the terminal behavior and external gate signals and requires no additional information from the application circuit. Experimental examples of several switch modules in low-voltage power converters are given. The experimental modules use power MOSFETs and give performance similar to that of synchronous rectifiers but with much greater flexibility. An example is noted in which a module configured to emulate a silicon controlled rectifier (SCR) shows voltage drops below 0.25 V at several amperes of forward current.>