Wide input range, high-efficiency magnetic resonant wireless power receiver

This article presents a full-CMOS receiver for magnetic resonant wireless battery charging system. A wide-input range CMOS multi-mode active rectifier is proposed for a magnetic resonant wireless battery charging system. The configuration is automatically changed with respect to the magnitude of the input AC voltage. The output voltage of the multi-mode rectifier is sensed by a comparator. Furthermore, the configuration of the multi-mode rectifier is automatically selected by switches as original rectifier mode, one-stage voltage multiplier or two-stage voltage multiplier mode. As a result, a rectified DC output voltage is from 7.5 to 19 V for an input AC voltage of 5-20 V. This chip is implemented using 0.35 mu m BCD technology with an active area of around 5x2.5mm(2). When the magnitude of the input AC voltage is 10V, the power conversion efficiency of the multi-mode active rectifier is about 94%.The efficiency of the receiver is about 60% when the distance between the transmitter and receiver is about 1m.