摘要
脉冲频率调制(PFM)开关变换器通过降低轻载时的开关频率而获得较PWM开关变换器更高的轻载效率,但传统的PFM控制电路复杂。这里设计一种简单的PFM控制电路,详细分析了PFM控制Buck变换器工作原理及工作过程,并通过理论分析与计算,给出了其最大导通时间的计算方法,导出了工作于电感电流连续导电模式Buck变换器的开关周期与输出电压的关系。仿真和实验结果验证了所设计电路的可行性及理论分析的正确性。
When the switching converter works in light load, pulse frequency modulation （PFM） can improve its effi- ciency by reducing switch frequency,but its control circuit is complex.Compared with traditional PFM Buck converter, a simple control circuit of PFM converter is proposed.The operation principle of proposed control circuit is investigated and analyzed based on Buck converter,and its maximal on-time is derived in detail.The relationship between output voltage and switch period when Buck converter operates in continues continuous mode（CCM） is also obtained.The simulation and experimental results verify the feasibility of the proposed circuit and the correctness of analysis results.
出处
《电力电子技术》
CSCD
北大核心
2011年第2期26-28,共3页
Power Electronics
基金
西南交通大学优秀博士学位论文培育项目
西南交通大学博士生创新基金~~
