摘要
为了解决开关电源PWM模式在轻载时的效率低下和PFM模式输出噪声频带比较宽,滤波难度大的问题,提出了一种新颖的开关电源调制模式—跳周期调制(SCM)结合可变极限电流比较器双环控制模式.提出SCM的控制机理和理论模式,SCM模式的效率比常规的PWM高,且基本上与负载无关;通过可变极限电流比较器对负载进行监测形成双环路控制模式,提高了电源的响应度,降低了开关电源的电磁干扰和输出纹波电压.分析了其效率和负载的关系,并与PWM、PFM调制模式进行了比较,得出SCM结合可变极限电流比较器双环控制模式是一种在不同负载下均有很高效率的调制模式,特别适用于在满载下工作时间相对不长的中小功率电源系统.
To solve the problem of PWM mode of switching power supply which efficiency is low in light load, and the problem of PFM mode which output noise bandwidth is wide, wave filtering is difficult, a novel switch power supply modulation mode is presented-skip cycle modulation （SCM） combining double-loop control mode with variable current limit comparator. The control mechanism and theory mode of SCM are proposed. The efficiency of SCM mode is high than conventional PWM mode, and is basically independent of load. The double-loop control mode is formed through the variable current limit comparator detects load. The Response speed of power supply is improved. The effect of EM/and the output voltage ripple are reduced. The relationship of its efficiency and load is analyzed, and compared with PWM and PFM mode. SCM combining double-loop control mode with variable current limit comparator is a kind of high efficiency modulation mode in different load, and is especially suitable for medium or small-power supply system which relative working time is not long in fully loaded.
出处
《电子器件》
CAS
2007年第3期935-938,共4页
Chinese Journal of Electron Devices
基金
国防基础科研项目资助<军用电子整机优化设计制造技术>(K1101020201)
