Disclosed is an integrated circuit, which includes a DTC block including DTCs, receiving a first reference signal and a first division signal, and outputting a second reference signal and a second division signal based on the first reference signal, the first division signal, and control codes, a TDC comparing phases of the second reference signal and the second division signal and outputting a comparison signal, a digital loop filter filtering the comparison signal, an oscillator generating an output signal based on the filtered comparison signal, a delta-sigma modulator outputting a first signal and a quantized noise signal based on first and second division ratio signals, a divider dividing a frequency of the output signal based on the first signal and outputting the first division signal, and a probability modulator generating the control codes based on the quantized noise signal. Probability density functions of the control codes are time-invariant.