Title :
A High Efficiency Dual-Mode Buck Converter IC For Portable Applications
Author :
Liou, Wan-Rone ; Yeh, Mei-Ling ; Kuo, Yueh Lung
Author_Institution :
Nat. Taipei Univ., Taipei
fDate :
3/1/2008 12:00:00 AM
Abstract :
This paper presents the design of a novel wide output current range dual-mode dc to dc step-down (Buck) switching regulator/converter. The converter can adaptively switch between pulsewidth modulation (PWM) and pulse-frequency modulation (PFM) both with very high conversion efficiency. Under light load condition the converter enters PFM mode. The function of closing internal idle circuits is implemented to save unnecessary switching losses. The converter can be switched to PWM mode when the load current is greater than 100 mA. Soft start operation is designed to eliminate the excess large current at the start up of the regulator. The chip has been fabricated with a TSMC 2P4M 0.35 mum polycide CMOS process. The range of the operation voltage is from 2.7 to 5 V, which is suitable for single-cell lithium-ion battery supply applications. The maximum conversion efficiency is 95% at 50 mA load current. Above 85 % conversion efficiency can be reached for load current from 3 to 460 mA.
Keywords :
CMOS integrated circuits; integrated circuit design; power convertors; pulse frequency modulation; pulse width modulation; secondary cells; PFM; PWM; TSMC; current 100 mA; current 460 mA; current 50 mA; dual-mode dc to dc step-down buck switching regulator-converter; efficiency 85 percent; efficiency 95 percent; load current; pulse-frequency modulation; pulsewidth modulation; single-cell lithium-ion battery supply applications; soft start operation; voltage 2.7 V to 5 V; Buck converter; dual-mode converter; integrated power management; pulse-frequency modulation (PFM); pulsewidth modulation (PWM);
Journal_Title :
Power Electronics, IEEE Transactions on
DOI :
10.1109/TPEL.2007.915047
