A signal generator includes N stages of cascaded control signal generating circuits, and is configured to receive K clock signals whose valid pulse edges are different from each other by a set time, an n-th control signal generating circuit of the N stages of control signal generating circuit generates a strobe signal based on a k-th clock signal of the K clock signals and sequentially outputs at least two different clock signals of other K−1 clock signals based on the strobe signal. A valid pulse edge of the k-th clock signal is within a valid pulse duration of a strobe signal of an (n−1)-th stage control signal generating circuit.