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

fYear

2008

fDate

25-27 May 2008

Firstpage

1332

Lastpage

1336

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;

fLanguage

English

Publisher

ieee

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

Type

conf

DOI

10.1109/ICCCAS.2008.4658012

Filename

4658012