Wireless Energy Harvesting IC for Low Power IoT sensor

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 (V-cap). When V-cap is higher than turn on voltage (V-in1), dynamic power switch is turned on then discharges the V-cap. Otherwise, when V-cap decreased lower than turn off voltage (V-in2), the dynamic power switch is turn off. The wireless energy harvesting circuit has been designed using a 0.18-mm HV (High Voltage) CMOS technology and its die chip size is a 1.17 mm x 1.17 mm. The DC-DC boost up converter can increase V-cap up t o 5.5 V for charging the battery. Also, it consumes about 10 mA (max) supply current at 1.8 V.