A transmitter circuit including a pre-driver circuit configured to receive a logic signal from a logic circuit and to generate a first signal driven by a first voltage, the pre-driver circuit including a transistor having a threshold voltage equal to or lower than a threshold voltage of a transistor included in the logic circuit, and a main-driver circuit configured to receive the first signal and generate a second signal driven by a second voltage, the main-driver circuit configured to output the second signal to an input/output pad, the main-driver circuit including a transistor having a threshold voltage which is equal to or lower than the threshold voltage of the transistor included in the logic circuit may be provided.