An Integrated One-Cycle Control Buck Converter With Adaptive Output and Dual Loops for Output Error Correction

Abstract

An integrated adaptive-output switching converter is presented. This converter adopts one-cycle control for fast line response and dual error correction loops for tight load regulation. A dc level shifting technique is proposed to eliminate the use of negative supply and reference voltages in the controller and make the design compatible with standard digital CMOS process. The design accommodates both continuous and discontinuous conduction operations. To further enhance the efficiency, dynamic loss control on the power transistors is proposed to minimize the sum of switching and conduction losses. The design can be extended to other dc-dc and ac-dc conversions. The prototype of the buck converter was fabricated with a standard 0.5-/spl mu/m digital CMOS process. Experimental results show that the converter is well regulated over an output range of 0.9-2.5 V, with a supply voltage of 3.3 V. The tracking speeds are 12.25 /spl mu/s/V for a 1.6-V step-up output change and 13.75 /spl mu/s/V for a 1.6-V step-down output change, respectively, which are much faster than existing counterparts. Maximum efficiency of 93.7% is achieved and high efficiency above 75% is retained over an output power ranging from 10 to 450 mW.