Wireless Energy Harvesting IC for Low Power IoT sensor

Abstract

A CMOS wireless energy harvesting IC is designed and fabricated for low power IoT sensor. A small single wireless energy harvester including dynamic power switch, ramp oscillator and DC-DC boost up converter is presented. It is consist of two blocks; one is a dynamic power switch, and the other is a DC-DC boost up converter with low power ramp oscillator. The dynamic power switch monitoring the voltage of off-chip storage capacitor (Vcap). When Vcap is higher than turn on voltage (Vin1), dynamic power switch is turned on then discharges the Vcap. Otherwise, when Vcap decreased lower than turn off voltage (Vin2), the dynamic power switch is turn off. The wireless energy harvesting circuit has been designed using a 0.18-μm HV (High Voltage) CMOS technology and its die chip size is a 1.17 mm × 1.17 mm. The DC-DC boost up converter can increase Vcap up to 5.5 V for charging the battery. Also, it consumes about 10 mA (max) supply current at 1.8 V.