A single-step, single-inductor energy-harvestingbased power supply platform with a regulated battery charger for mobile applications

An energy-harvesting-based power supply platform for mobile applications such as cell phones, tablets and laptops is presented. The proposed platform combines the process of Maximum Power Point Tracking (MPPT) from the energy-harvesting source with the process of generating a regulated power supply together in a single power conversion step. Therefore, it achieves higher efficiency than conventional platforms where two cascaded power conversion stages are required to maintain both MPPT and voltage regulation. Moreover, the proposed platform incorporates a battery charger that leverages the excess energy beyond the load demand to charge a battery in a regulated manner following the Constant Current Constant Voltage (CCCV) procedure, and thus ensures safe charging compared to conventional platforms. When the harvested energy is less than the load demand, the charger provides the difference by routing energy from the battery to the load in order to maintain regulation at all times. The proposed platform is implemented in 0.25μm standard CMOS technology and system level simulations are presented to demonstrate the system functionality under various operating scenarios.