A Reconfigurable Wireless Power Receiver with Shared-Inductor Buck-Boost Converter for NFC-Powered Battery-Less Electronic Shelf Label

This paper proposes a reconfigurable wireless power receiver for NFC-powered battery-less electronic shelf label (ESL). It achieves both 13.56-MHz AC-DC regulating rectification and 1-MHz DC-DC buck-boost conversion by sharing the receiver coil and power stages. Considering that wireless power may not always be sufficiently available, the rectifier employs a storage capacitor to ensure charging stability under conditions of low input received power. Additionally, a bi-directional buck-boost converter (BD-BBC) has been proposed to achieve dual-output by sharing a core with a rectifier. It also enables the regulation of output voltage across a broad range of input voltages, thereby enhancing system design flexibility. For the storage capacitor serving as the input source for the BD-BBC, its utilization can also be improved. The chip is fabricated using a 0.18-μm CMOS process. The measurement results demonstrate a peak AC-DC rectification efficiency of 92.3% and a peak DC-DC conversion efficiency of 80.2% across a wide input voltage range.