A 10MHz 80μW 67 ppm/°C CMOS reference clock oscillator with a temperature compensated feedback loop in 0.18μm CMOS

Abstract

A 10MHz, 80μW CMOS reference clock oscillator is presented in 0.18μm CMOS. The proposed oscillator employs a supply-regulated ring-oscillator in a temperature compensated feedback loop, which minimizes the frequency sensitivity to supply and temperature variations. The clock oscillator achieves frequency variation of less than ±0.05% against supply variation of 1.2V ~ 3V and ±0.4% against temperature variation of −20°C ~ 120°C. In addition, low power consumption is achieved by using sub-threshold bias circuits.