Title :
A dual-mode step-up DC/DC converter IC with current-limiting and EMI reduction techniques
Author :
Liou, Wan-Rone ; Chen, Ping-Hsing ; Rosales, Marynelle ; Yeh, Mei-Ling ; Kuo, Chun-Ting
Author_Institution :
Grad. Inst. of Electr. Eng., Nat. Taipei Univ., Taipei
Abstract :
This paper presents a novel dual-mode step-up 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 can reach 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.
Keywords :
DC-DC power convertors; PWM power convertors; electromagnetic interference; pulse frequency modulation; EMI reduction; current-limiting technique; dual-mode step-up DC/DC converter; load current; pulse-frequency modulation; pulse-width modulation; soft-start circuit; variable-sawtooth frequency circuit; Circuits; DC-DC power converters; Electromagnetic interference; Frequency conversion; Inductors; Pulse width modulation; Pulse width modulation converters; Switches; Switching converters; Voltage control;
Conference_Titel :
Communications, Circuits and Systems, 2008. ICCCAS 2008. International Conference on
Conference_Location :
Fujian
Print_ISBN :
978-1-4244-2063-6
Electronic_ISBN :
978-1-4244-2064-3
DOI :
10.1109/ICCCAS.2008.4658012
