180 nm CMOS Cold-Start Energy-Aware Switching Circuit for Energy Management in WPT Receiver

Abstract

Modern electronic devices offer high level performance at low power consumption. This opens a possibility to have battery-less electronic devices. Energy harvesting and wireless power transfer are popular methods to power such devices. Both methods require energy management. The focus of this paper is on energy management for receiver circuit in a wireless power transfer system. More specifically, the paper focuses on a cold-start energy-aware switching circuit which is a key building block of energy management in WPT receiver. Proposed integrated circuit is designed to operate in discontinuous mode and can supply power to load circuits which require higher voltage and current levels than available from the WPT receiver. Unlike most similar solutions who are fully integrated, the proposed integrated circuit uses two external trimmer resistors to adjust required voltage levels and the power consumption. External trimmer resistors also allow to compensate for the process variations of IC fabrication. Developed circuit is fabricated in 180 nm TSMC CMOS technology and evaluated through laboratory measurement. Cold-start functionality and energy-aware switching are verified through standalone measurements and measurements with WSN node powered through developed circuit. The power consumption of cold-start switching circuit is measured less than 1 µW.