A Low-Power CMOS Current Reference for Piezoelectric Energy Harvesters

This article proposes a nanoscale complementary metal-oxide-semiconductor (CMOS) current reference design for low power analog and digital devices. A self-biased circuit is developed within the current reference. The current reference can compensate for temperature changes and voltage fluctuations. Simulation results showed a low current around 12 nA. The design is capable of working in a broad range of power supply voltages. In the interface with 0.35 μm fabrication process, a bias voltage is generated with currents in the nanoampere range. The present current reference is qualified to be used in digital-analog circuits, such as operational amplifiers or oscillators, and is designed to be suitable for energy harvesting interfaces, because of the high efficiency and low power consumption.