Title :
An analytical equation for the oscillation frequency of high-frequency ring oscillators
Author :
Docking, Stephen ; Sachdev, Manoj
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Waterloo, Ont., Canada
fDate :
3/1/2004 12:00:00 AM
Abstract :
An analytical equation for the oscillation frequency of a ring oscillator is derived. The derivation is done using a novel method which does not need to find an expression for the delay of each stage. The resulting equation includes the effect of time-varying parasitics. It also includes the effect of the gate resistance, which has a large effect on the oscillation frequency at high frequencies. Measurement results of ring oscillators fabricated in a 0.18-μm CMOS process show that the resulting equation has an average error of 8% over a large range of parameter variations.
Keywords :
electromagnetic oscillations; radiofrequency oscillators; CMOS process; gate resistance; high-frequency ring oscillators; oscillation frequency; time-varying parasitics; CMOS process; Circuit simulation; Delay; Electrical resistance measurement; Equations; Frequency; High speed integrated circuits; Integrated circuit measurements; Ring oscillators; Voltage-controlled oscillators;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2003.822778
