A Dual-Output Wireless Power Transfer System With Active Rectifier and Three-Level Operation

This letter presents a 6.78 MHz wireless power transfer (WPT) system for wirelessly powered flash drives that need multiple supplies with a total power of sub-1 W. A new architecture that merges an N-level single-inductor multiple-output switching converter with a multistage rectifier is proposed for the WPT receiver, and the regulated outputs attain small ripples. A prototype of a 2X active rectifier that merges with a three-level single-inductor dual-output dc-dc converter is implemented in a 0.35 μm CMOS process.