10 mV – 1V step-up converter for energy harvesting applications

This paper presents an ultra-low-voltage step-up converter for energy harvesting applications, which is able to operate from supply voltages below the thermal voltage kT/q. The operation of the main blocks of the converter, namely an enhanced swing ring oscillator and a Dickson charge pump, both operating at ultra-low voltage, is described. The extremely low voltage operation, made feasible through the arrangement presented, is demonstrated via a prototype built with off-the-shelf devices and zero-VT transistors in a 130 nm CMOS technology. The prototype generates a DC output equal to 1V at current consumptions of 10 nA and 1 μA from input voltages of 10 and 25 mV, respectively.