A Resonant Current-Mode Wireless Power and Data Receiver for Loosely Coupled Implantable Devices

This article proposes a current-mode (CM) receiver for a wireless power transfer (WPT) application that receives both power and data from the transceiver. The proposed CM receiver decreases the voltage stress applied to transistors to store a larger amount of power in its LC tank, and this charges the battery without any residual power. Accordingly, the receiver achieves the highest maximum receiver efficiency of 92.6% among the state-of-the-art CM receivers at an input power of 10.89 mW. The proposed CM receiver receives data along with the power by using energy-shift keying (ESK), which is the proposed data transfer method for the CM receiver. Due to ESK, the receiver achieves a maximum data rate of 100 kb/s while consuming negligible power for receiving the data. A prototype chip fabricated in a 180-nm CMOS process occupied an area of 0.43 mm x 0.49 mm, and a receiver coil was implemented as a printed spiral coil with dimensions of 6 mm x 6 mm.