A 12-W 96.1-Efficiency eFuse-Based Ultrafast Battery Charger Supporting Wireless and USB Power Inputs

摘要

Portable devices (e.g. smartphones) are typically equipped with Lithium (Li)-ion batteries and in-situ chargers [1],[2]. 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 [3],[4] – the interest of this paper – is highly desirable to offer a wide input voltage range and a flexible output current [5],[6]. However, present-art switching charger designs [3]–[6] 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.