| Output current of automotive back converter has a wide range such as 10 to 210 A. Generally, the efficiency of multi-phase buck converter is designed high when its loads is heavy. However, the output current of buck converter do not only work at heavy loads because of its load changes. Therefore, it is necessary to consider the efficiency not only at heavy load but also at middle and light load. In order to maintain the efficiency high, it is effective to dynamically adjust the number of phases according to load conditions. In this paper, we propose a control method for hysteretic controlled DC-DC converter with new current sharing technique. |