峰值电流模BUCK变换器的建模及稳定性设计  

Modeling analysis and stability design of peak-current mode BUCK converter

作　　者：叶强[1] 王泽宇[2] 来新泉[1] 

机构地区：[1]西安电子科技大学电路CAD研究所,陕西西安710071 [2]西安电子科技大学超高速电路设计与电磁兼容教育部重点实验室,陕西西安710071

出　　处：《华中科技大学学报（自然科学版）》2014年第2期31-34,共4页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：中央高校基本科研业务费专项资金资助项目(K50511020031)

摘　　要：基于小信号建模思想,建立了电感电流连续模式(CCM)下的BUCK变换器完整的小信号模型,推导出了控制-输出传递函数.通过分析电流采样对系统稳定性的影响及控制-输出传递函数中的零极点位置,提出一种电压环补偿电路,该结构产生了一对频率不同且随Cm变化的零点和极点,可用以灵活地对环路带宽及相位裕度进行微调.利用Matlab及Hspice仿真,验证了该建模方法及补偿方案的正确性,仿真结果表明:补偿后的变换器低频增益可达55dB,带宽为225kHz,相位裕度达到74°,环路在各种负载下均表现出优良的稳定性.Based on the small signal modeling method ,a complete BUCK converter small signal model operating in current-continue-mode （CCM ） was established ,with a control-to-output transfer function derived .T hen ,by detailed calculating the zreos and poles in the transfer function of control-stage loop as well as analysing the effect of the current sensing on the stability of the whole system ,the reason to compensate the voltage loop was illustrated and a novel compensation method was proposed .Prac-tices made by both Matlab and Hspice showed that the modeling and the compensation methods were correct ,and simulation results showed that the low frequency gain of the converter system was as high as 55 dB ,with a bandwidth of 225 kHz ,and the phase margin was 74° ,which made the loop sta-ble at various load conditions .

关 键 词：电压环路补偿 电流模控制 小信号模型 斜波补偿 环路补偿 

分 类 号：TN401[电子电信—微电子学与固体电子学] TN432