Title :
An Efficiency-Enhanced DCM Buck Regulator With Improved Switching Timing of Power Transistors
Author :
Lee, Hoi ; Ryu, Seong-Ryong
Author_Institution :
Dept. of Electr. Eng., Univ. of Texas at Dallas, Richardson, TX, USA
fDate :
3/1/2010 12:00:00 AM
Abstract :
This brief presents circuit techniques to improve the power efficiencies of a discontinuous-conduction mode (DCM) buck regulator for portable applications. A switched-capacitorcomparator-based adaptive dead-time control is developed to provide fast and accurate sensing and comparison for optimizing the switching timing of power transistors and thus simultaneously minimizing the power losses caused by the reverse inductor current, body-diode conduction, and shoot-through current. A new ringing suppression circuit is also proposed not to affect the dead-time of power transistors during switching instants for additional power savings. Implemented in a 0.35-¿m standard CMOS process, the proposed DCM buck regulator has only ¿20-ns sensing delay and achieves > 84% power efficiency for load currents of > 5 mA when the input voltage is 1.8 V.
Keywords :
CMOS integrated circuits; adaptive control; comparators (circuits); power convertors; power transistors; switched capacitor networks; CMOS process; adaptive dead-time control; body-diode conduction; buck regulator; discontinuous-conduction mode; power losses; power transistors; reverse inductor current; ringing suppression circuit; shoot-through current; size 0.35 mum; switched-capacitor comparator; switching timing; voltage 1.8 V; Adaptive control; CMOS process; Delay; Inductors; Power transistors; Programmable control; Regulators; Switching circuits; Timing; Voltage; Buck regulator; dc–dc converter; dead-time control; discontinuous-conduction mode (DCM); pulsewidth modulation;
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2010.2043380
