摘要
开关电源工作在高频开关状态下,是电子设备主要的电磁干扰源。从麦克斯韦方程出发,分析了开关电源产生电磁干扰(EMI)的主要原因。介绍了开关电源传统的驱动电路及解决EMI的方法,提出了一种结构新颖的驱动电路。该电路不仅具有功率管开启时间不随其输入电容变化的优点,而且采用两段式的方法关闭功率管,有效减缓了di/dt和dv/dt,同时,保证系统具有较高的工作效率。实验结果表明,提出的驱动电路在无效率损失的情况下,经EN55022Class B标准测试,将水平1m的峰值裕度提高15.40dB,垂直3m的峰值裕度提高16.19dB。
Switching-mode power supply,which operates at high frequency switching mode,is the major source of electromagnetic pollution from electronic equipments.Main reasons for electromagnetic interference generated by switching-mode power supply were analyzed using Maxwell equation.Traditional driving circuit for switching-mode power supply and solutions to EMI were described.A driving circuit with new structure was proposed,in which the turn-on time of power transistor did not vary with input capacitance,and two-stage approach was used to turn off power switch,thus achieving both high efficiency and low EMI.Experimental results showed that,according to EN55022 Class B standard,the proposed circuit increased peak margins by 15.4 dB and 16.19 dB at 1 m horizontally and 3 m vertically,respectively,without efficiency loss.
出处
《微电子学》
CAS
CSCD
北大核心
2011年第5期676-680,共5页
Microelectronics
关键词
开关电源
驱动电路
电磁干扰
Switch-mode power supply
Driving circuit
Electromagnetic interference
