High-frequency modeling for the nonlinearities in buck converters

To analyze the high-frequency performance for buck converters, this paper proposes the models for the nonlinearities in the circuit. Different modulation types are compared based on their influence on the sideband effect and the control bandwidth limitations. The possible benefit from the double-edge modulation and its limitations are discussed. In addition, the nonlinearity of the switches is modeled to include the input voltage variations. A general high-frequency model is achieved according to the combination of the two nonlinearities, i.e. the PWM comparator and the switches. Simulation and experimental results are presented as verifications