A Systematic and Unified Approach to Modeling Switches in Switch-Mode Power Supplies

Abstract

This paper describes a new, systematic, and unified approach to model the low-frequency behavior of power switches in Switch-Mode Power Supplies (SMPS). This approach starts with a simplification of the switching converter circuit to a Minimum Separable Switching Configuration (MISSCO) containing all power switches but a minimum number of other components, before analysis on the MISSCO is carried out. Then by making use of an impulse-response method and averaging technique, a set of equations describing the low-frequency behavior of the MISSCO are derived. The resultant equations can be used to generate a low-frequency equivalent circuit of the MISSCO, which can then be combined with the rest of the SMPS circuit to form a complete equivalent circuit.