An Enhanced Control Algorithm for Improving the Light-Load Efficiency of Noninverting Synchronous Buck-Boost Converters

A loss reduction algorithm at light loads is needed to increase the overall efficiency of noninverting synchronous buck-boost dc-dc converters. Inductor current ripple generates most of the total loss at light loads. Thus, a ripple current reduction algorithm is an effective method of increasing light-load efficiency. This letter proposes a control algorithm for increasing the light-load efficiency by controlling the inductor current ripple. To achieve the optimal control of the inductor current, a maximum efficiency tracking scheme is implemented. Experimental results verify that the proposed algorithm significantly improves the light-load efficiency; at a 10% load condition, the efficiency is approximately 3.19% higher than that of the conventional algorithm.