3.6 GHz CMOS ring oscillator with low tune voltage sensitivity and temperature compensation

In this paper we present the design of a temperature compensated low-tune-voltage-sensitive CMOS ring oscillator in 40nm standard CMOS technology. The oscillator has an overall frequency range from 3.1 GHz to 3.6 GHz. The effect of temperature variations on the frequency span has been tuned out by an IPTAT (inversely proportional to absolute temperature) current reference. In this work, using a coarse-fine tuning mechanism lowers the tune range sensitivity of the oscillator, which is usually represented as K_VCO. The achieved K_VCO is around 490 MHz/V with 400 mV tune voltage sweep. The area and the power consumption of the ring oscillator are 0.0056 mm² and 0.9 mW.