An Independently Controlled Magnetic Coupling Multi-Output Buck Converter With Mixed Modes for Unbalanced Loads

Abstract

This article proposes a magnetic coupling multi-output (MCMO) buck converter which can work in a mixture of continuous conduction mode (CCM) and discontinuous conduction mode (DCM) to meet the demand for unbalanced loads including one heavy load and other light loads. For the output with heavy load, its current is equal to the continuous magnetizing current of coupled inductor, while the discontinuous leakage inductor current is distributed to the outputs with light loads. In comparison with the conventional single-inductor-multi-output (SIMO) converter working in CCM or DCM, the proposed converter can obtain small spike current and independent control simultaneously. In addition, only a magnetic core is utilized and thus the favorable advantage of reduced cost and volume is retained. In this article, in order to obtain a better understanding of the proposed converter, an example magnetic coupling dual-output (MCDO) one is thoroughly analyzed, and afterwards, experimental results are also demonstrated to verify the theoretical analysis.