Modeling and Frequency-Domain Characterizations of PWM Regulators

Designing a switched mode power supply (SMPS) can be a daunting task if all requirements are to be met with as few revisions as possible. Selecting the right PWM control chip and obtaining optimum compensation can be very time-consuming procedure. The design parameters are not always given in the datasheet with the desired accuracy or a simulation model may not be available. This paper presents the steps that a designer can take to optimize the dynamic response of a SMPS. Simulation and experimental models are presented and compared in terms of their usefulness in designing a closed loop system. The key discrepancies between simulation and experiment are discussed in order to help in designing better simulation models for closed loop operation.