New Modeling Approach and Equivalent Circuit Representation for Current-Mode Control

作者：Li Jian^*; Lee Fred C

来源：IEEE Transactions on Power Electronics, 2010, 25(5): 1218-1230.

DOI：10.1109/TPEL.2010.2040123

• Current-mode control
• describing DF)
• modeling

Constant ON-time current-mode control has been widely used to improve light-load efficiency, because it can reduce the switching frequency to save switching-related loss. Therefore, an accurate model for constant ON-time control is indispensable to system design. However, available models for constant ON-time control are unable to provide accurate physical insight or predict system response very well. This paper introduces a new modeling approach for constant ON-time control. The inductor, the switches, and the pulsewidth-modulated modulator are treated as a single entity and modeled based on the describing function method. The fundamental difference between constant ON-time control and constant-frequency peak-current-mode control is analyzed through the proposed model. This proposed modeling method can be easily extended to other current-mode controls, including V(2) controls. A simple equivalent circuit representation is proposed for the sake of easy understanding and simulation of current-mode controls. Simulation and experimental results are used to verify the proposed model.

• 出版日期2010-5