A Unified Approach to Modeling High-Frequency Effects in Current Mode Controlled Pulse Width Modulated Switching Converters

摘要

This paper presents a unified and general approach to modeling high-frequency dynamics of peak-current mode (PCM) and average current mode (ACM) controlled pulse width modulated switching converters. A discrete-time model is developed that takes into account sampling and small-signal gain associated with pulse-width modulation. Furthermore, a unified view of PCM and ACM is presented, a general underlying structure is identified, and it is shown that the unified modeling approach can accurately predict high-frequency dynamics of both control strategies. The modeling results, including a general stability condition that applies to both PCM and ACM cases, are verified by simulations.