A 300mV Low-voltage start-up circuit for energy harvesting systems

This paper presents a start-up circuit for low voltage energy harvesting applications. The proposed approach incorporates analog memories in the design of a low-voltage ring oscillator along with an efficient charge pump capable of converting voltages in the sub-700mV range to voltages suitable for circuit operation. Simulated results using 0.5 mu m CMOS technology resulted in a circuit capable of working for input voltages as low as .300V. The start-up circuit containing an eight-stage charge pump is able to increase a typical photodiode voltage of .480V to 3.6V.