On-Chip Indoor-Outdoor Cold-Startup Circuit for Miniature Photovoltaic Cells

This work presents experimental results from an integrated low-power, low-area Dickson charge pump circuit, using 7.5 mm2 miniature photovoltaic cells, for cold-start operation. The proposed cold-start topology presents successful operation, both for indoor and outdoor lighting conditions, for input voltages as low as 440 mV. The cold-start circuit is implemented and fabricated in a 0.18 um CMOS process. The chip active area, occupied by the designed cold-start block, is 0.224 mm2. The area-efficient and low-power design of the presented cold-start circuit makes it ideal for micro-energy harvesting applications.