A 12 nA low frequency oscillator

In this work, a 12 nA current consumption, 27 Hz (nominal) square wave oscillator is presented. The circuit includes self-bias current and voltage references, and can be powered with a wide range supply voltage from 1.6 to 5.0 V. The circuit is designed in a standard 0.6 μm MOS technology, with most of the transistors operating in weak inversion. The oscillator is intended as part of the next generation of portable or autonomous devices, powered by microbatteries or energy harvesting systems.