Nonlinear modulation for voltage-mode controlled switching converters with fast input transient performance

In this paper, the nonlinear modulation, including nonlinear single-edge modulation (NSEM) and nonlinear dual-edge modulation (NDEM), for voltage-mode controlled switching converters are proposed to provide fast input transient performance, and the corresponding nonlinear modulation circuits are presented. The gain of nonlinear modulation circuit plays an important role in keeping the output voltage stable and obtaining excellent input transient response. The method to deduce the nonlinear gain is general and applicable for different switching converters. Moreover, the simulation results show that voltage-mode controlled buck converter with NDEM benefits with better input transient response and steady state performance than improved one-cycle control and peak current control when input voltage varies. In addition, voltage-mode control with NDEM also presents much better input transient performance than conventional voltage-mode control in boost converter.