An apparatus of performing a clock skew adjustment between N clock signals. 2(N−1) skew sensors are configured as successive pairs k, each pair k having a first skew sensor and a second skew sensor. The first skew sensor receives a third clock signal obtained by delaying the first clock signal by a first delay and a fourth clock signal obtained by delaying the second clock signal by a second delay, and generates first information based on the third and fourth clock signals. The second skew sensor receives a fifth clock signal obtained by delaying the first clock signal by a third delay and a sixth clock signal obtained by delaying the second clock signal by a fourth delay, and generates second information based on the fifth and sixth clock signals. A skew controller performs the clock skew adjustment based on the first and second information.