Ring oscillator having logic gates interconnected by spiral signal lines

摘要

A ring oscillator circuit of one aspect includes a plurality of logic gates connected in cascade in a ring form and a plurality of signal lines each disposed between adjacent ones of the plurality of logic gates, and one of the signal lines is disposed in a spiral form in a pair together with another signal line. A ring oscillator circuit of another aspect includes a plurality of logic gates connected in cascade in a ring form and a plurality of signal lines whose wiring layout is made using wiring layers of a multi-layer structure and which are disposed between adjacent ones of the plurality of logic gates, and one of the signal lines is disposed spirally in such a manner as to be close to itself at portions thereof in at least two of the wiring layers of a multi-layer structure. When such a layout of the signal lines is employed, the difference between the frequency of the pulses actually output and the frequency of the output pulses based on simulation can be reduced to minimum.