A 2.06μW/MHz, 5.05-MHz, -40-125°C, 22ppm/°C Relaxation Oscillatior with Single Comparator Control

Abstract

In this paper, a 5.05MHz, 2.06μW/MHz, 22ppm/°C relaxation oscillator working as temperature varies from -40°C to 125°C and supply voltage varies from 1.1V to 2V is proposed and designed in a 180nm CMOS process. By using a single comparator control method and a reduced charging/discharging capacitance, the energy-per-cycle figure of merit reaches 2.06μW/MHz. With on-chip voltage and current reference and optimized comparator delay times, the output frequency has a temperature coefficient of only 22ppm/°C. The frequency changes for only 16% when supply voltage varies from 1.1V to 2V.