A Novel Pull-Up Active-Clamping Wireless Charging Circuit with Low Cost and Voltage Stress

The traditional single-switch circuit has the advantages of fewer components, no shoot-through problems, and suitability for high-frequency wireless charging applications. However, because high voltage stress switch, bulky inductor, narrow soft-switching range, its power applications have some limitations. To relieve this problem, paper proposes a pull-up active-clamping circuit, which not only offers low component count with inductors, but also greatly reduces switch stress. In addition, wide range soft switching can be achieved by designing primary-side compensation capacitor. A detailed parametric design method is given compared existing circuits from aspects stress, count, efficiency, cost, so on. Finally, 1 MHz, 180 W system built to verify proposed method.