A Dual-Mode Step-up DC/DC Converter IC with Current-Limiting and EMI Reduction Techniques  

作　　者：Wan-Rone Liou Ping-Hsing Chen Marynelle L. Z. Rosales Yeh Chun-Ting Kuo Mei-Ling Yeh 

机构地区：[1]the Graduate Institute of Electrical Engineering, National Taipei University, San Shia, Taipei, 23741, Taiwan, China [2]the Department of Electrical Engineering, National Taiwan Ocean University, Keelung, Taiwan, China

出　　处：《Journal of Electronic Science and Technology of China》2008年第3期279-283,共5页中国电子科技（英文版）

基　　金：the National Science Council of Taiwan, China, under Grant No. NSC 95-2221-E-305010.

摘　　要：This paper presents a novel dual-mode step-up （boost） DC/DC converter. Pulse-frequency modulation （PFM） is used to improve the efficiency at light load. This converter can operate between pulse-width modulation （PWM） and pulse-frequency modulation. The converter will operate in PFM mode at light load and in PWM mode at heavy load. The maximum conversion efficiency of this converter is 96%. The conversion efficiency is greatly improved when load current is below 100 mA. Additionally, a soft-start circuit and a variable-sawtooth frequency circuit are proposed in this paper. The former is used to avoid the large switching current at the start up of the converter and the latter is utilized to reduce the EMI of the converter.This paper presents a novel dual-mode step-up （boost） DC/DC converter. Pulse-frequency modulation （PFM） is used to improve the efficiency at light load. This converter can operate between pulse-width modulation （PWM） and pulse-frequency modulation. The converter will operate in PFM mode at light load and in PWM mode at heavy load. The maximum conversion efficiency of this converter is 96%. The conversion efficiency is greatly improved when load current is below 100 mA. Additionally, a soft-start circuit and a variable-sawtooth frequency circuit are proposed in this paper. The former is used to avoid the large switching current at the start up of the converter and the latter is utilized to reduce the EMI of the converter.

关 键 词：Boost converter dual-mode converter integrated power management pulse-frequency modulation （PFM） pulse-width modulation （PWM） 

分 类 号：TM46[电气工程—电器]