A 42-mV startup ring oscillator using gain-enhanced self-bias inverters for extremely low voltage energy harvesting

This paper presents a ring oscillator (ROSC) capable of operating at an extremely low supply voltage. The proposed ROSC consists of gain-enhanced self-bias inverters. The voltage gain of the proposed inverter is improved by controlling the body bias voltages. Measurements of a prototype chip demonstrated that our proposed ROSC can operate at an extremely low supply voltage of 42 mV. (C) 2020 The Japan Society of Applied Physics