A low power low supply sensitivity current-mode relaxation oscillator

Abstract

This paper presents a design of a 100 kHz 0.54 µW fully integrated current-mode relaxation oscillator. The transistors in the sub-threshold region, the current-mode comparator, the current-starving RS flip-flop are used to reduce the power consumption. Meanwhile, the employing of the current-starving RS flip-flop significantly reduces the sensitivity of the frequency to supply voltage fluctuation. The temperature coefficient is 51 ppm/°C from −40 to 85°C, and the line regulation is −0.40%/V over a supply voltage range from 1.0 to 2.0 V. This oscillator is designed in SMIC 0.18 µm CMOS technology and operates at minimum supply voltage of 1.0 V with drawn current of 540 nA at room temperature.