A wirelessly powered charging system for use in implanted biomedical applications is proposed. A sinusoidal ac voltage received through the magnetic inductive link, which is driven by a Class-E power amplifier, is input to an active rectifier, which converts it to an unregulated dc supply voltage. A regulator circuit then provides dc-dc conversion to produce a specific dc voltage to charge a miniature, bio-compatible pin-type Lithium-Ion battery.
An integrated circuit, comprised of the active rectifier and the regulator, was designed to meet the requirements of the system and was fabricated in the AMI 0.5-μm CMOS process. Tests were performed to verify the functionality and performance of the circuit.