Integration of energy-recycling logic and wireless power transfer for ultra-low-power implantables

This paper presents an integration of energy-recycling logic circuits with a wireless power transfer receiving module for ultra-low-power applications, such as transcutaneous biomedical implantables. In the prototype design, one inductive coil implanted inside the body receives wireless power and supplies the following electronics. While part of the loading is composed of conventional CMOS logics, the rest is implemented with energy-recycling logic circuits. Energy-recycling logic and the associated adiabatic operation achieve excellent energy efficiency by transferring and recycling energy between digital logic blocks along with the signal propagation. The required AC supplies further lead to a natural integration with wireless power transfer and therefore obviate the need for a rectifier that contributes to substantial power loss. As a proof of concept, a finite-impulse-response filter is designed in 90-nm CMOS process. Simulation results show a 59.3% power reduction as compared to static CMOS counterpart.