Low-Voltage Indoor Energy Harvesting Using Photovoltaic Cell

Abstract

This work presents a low-voltage indoor energy harvesting using photovoltaic cell. The system doesn\'t use a dc-dc converter to boost the output voltage so that large external inductors and large capacitors are eliminated. A rechargeable battery is connected to the output for storing the energy. No other external components are needed in the system. A test chip is implemented using a 0.18um CMOS process with a chip area of 0.85x0.85mm(2) and a power consumption of 272uW. This solar cell provides a voltage of 0.4V similar to 0.55V to the test chip at a minimum illumination of 61 similar to 625 Lux. A maximum efficiency of 54% can be obtained when the supply voltage is 0.5V.