Portable devices (e.g. smartphones) are typically equipped with Lithium (Li)-ion batteries and in-situ chargers ,. Due to the increasing demand for fast charging, the battery charger requirements are becoming stringent, demanding smooth mode transition, high power-efficiency, large output power, and small form-factor. In comparison with linear or switched capacitor topologies, an inductor-based switching charger ,-the interest of this paper-is highly desirable to offer a wide input voltage range and a flexible output current ,. However, present-art switching charger designs - suffer from the difficulty to meet these requirements because of their potential issues, including instability at mode transitions, excessive hard-switching power loss, single-input power rail limitation, and bulky output inductor.