Power management unit for multi-source energy harvesting in wearable electronics

This paper presents a power management unit (PMU) architecture for multi-source energy harvesting system in wearable devices. The energy harvesting system utilizes a thermal and vibration harvesters as energy sources. In addition, the PMU is designed to control the harvested energy as well as to manage the power delivered to an ECG processor. Further, the PMU generates different signals to enable and disable the processor depending on the available energy. The ECG processor analyzes ECG signals and predicts ventricular arrhythmia (VA). The ECG processor is a multi-voltage design that uses a 0.6V for the processing core and a 1V for the SRAM. Simulation results of the PMU shows the operation of the ECG processor at different energy states in different modes of operation. The proposed architecture could help wearable electronics to run at their optimum energy point to increase their life time.