Design and implementation of current sharing control for switching power supply

Design and implementation of a simple current sharing control technique, based on the concept of the differential-mode choke, is presented herein, which is applied to two-phase synchronously-rectified (SR) buck converter. This current-sharing structure is quite simple. In this circuit, a synchronously-rectified (SR) switch is used to upgrade the efficiency, two phases with phase shift of 180° is employed to reduce the inductor current ripples, and coupling output inductors is utilized to further decrease the inductor current ripples. In this paper, the detailed basic operating principles, together with mathematical derivations, are firstly described, and secondly some simulated and experimental results are offered to demonstrate the proposed control strategy.