A Bias Supply Scheme for a Self-Powered EMS for Battery-less IoT Applications Powered by Electromagnetic Energy Harvesters

This paper presents a bias supply scheme for a self-powered energy management system (EMS) for internet of things (IoT) applications powered by ultra-low-voltage electromagnetic energy harvesters (EMEHs). The bias supply scheme utilizes the first two cycle of the EMEH voltage to provide a start-up voltage, with the help of a two-stage Villard charge pump, to the control circuit. Then, it utilizes the unregulated intermediate voltage of the EMS alongside a single stage charge pump with a floating capacitor to sustain the operation of the system. The bias supply scheme is completely passive and can be implemented with off-shelf discrete components or on a standard technology node. The EMS is also capable of providing a tight output voltage regulation using a tiny magnetic substrate based de-de converter. Experimental results show the effectiveness of the presented solution to operate with an ultra-low-voltage EMEH that has a damped voltage characteristics from 0. 8V to 10m V. Also, the tiny magnetic substrate based de-de converter provides a tight regulated voltage of 1.2V at 5mA for group of wireless sensors while achieving efficiency around 83% for load currents between 100μA and 200mA.