US Patent 9425779 Delay circuit

A delay circuit may include a delay path including a fine delay line and a coarse delay line, a replica delay path including a replica fine delay line and a replica coarse delay line, and a tuning unit that compares a phase of a first signal obtained by delaying an input signal through the delay path with a phase of a second signal obtained by delaying the input signal through the replica delay path, and generates a tuning code in a tuning mode.