A decision feedback equalizer includes a positive signal line, a negative signal line, a sense amplifier, a feedback driver, a load unit, a differential driver, and a charge pump. The differential driver maintains a difference between the first voltage of the positive signal line and the second voltage of the negative signal line at a last time point of the normal period to be equal to or greater than the reference voltage by adjusting strength of the positive input current corresponding to a positive input signal and strength of the negative input current corresponding to a negative input signal based on a temperature signal. The charge pump provides a positive offset voltage and a negative offset voltage to the positive signal line and the negative signal line, respectively. The positive offset voltage and the negative offset voltage are used to maintain an average voltage of the first voltage and the second voltage at the last time point of the normal period at a first value.