In a driver circuit for driving a pair of data lines, the amplitude of a differential input signal is reduced from 2.5 V to 0.6 V, which is smaller than a conventional lower-limit source voltage (approximately 1.5 V). The amplitude of the differential signal transmitted through the pair of data lines is amplified to 2.5 V by an amplifying circuit and the resulting signal is then latched by a latch circuit. After the latching by the latch circuit, the operation of the amplifying circuit is halted. The driver circuit is constituted solely by a plurality of NMOS transistors so as not to increase a leakage current flowing in the off state. Here, the threshold voltage of the NMOS transistor positioned on the ground side is reduced to a conventional lower-limit value (0.3 V to 0.6 V), while the threshold voltage of the NMOS transistor on the power-source side to a value lower than the above lower-limit value (0 V to 0.3 V), thereby enhancing a driving force of the NMOS transistor on the power-source side.