Power Feedback Control Unit for Closed-Loop Wirelessly Powered Biomedical Implants

Effective power management is crucial in designing wirelessly powered implants that have a long operational lifetime. It ensures that the received power is optimized for efficient operation and prevents damage caused by excessive or insufficient powering. This brief presents a power feedback control unit for wirelessly powered implanted biomedical devices, which includes an implanted voltage level detector and limiter. The feedback control bits can be transmitted through the link to the external unit as uplink data communication, or used to autonomously prevent overvoltage in worst-case scenarios. This design is implemented and fabricated in a 180nm CMOS process, which can be used for the power conversion chain of wirelessly powered biomedical implanted devices. The system consumes 144 $\mu \text{W}$ at a supply voltage of 1.8V and a chip area of 0.02255 mm2.