A transmitter circuit is provided. The transmitter circuit has a first transmission node and a second transmission node and includes a first resistor, a second resistor, a third resistor, a fourth resistor, and a driving circuit. The driving circuit includes a first transistor group, a second transistor group, a third transistor group, and a fourth transistor group. The first resistor is coupled between a first output terminal and the first transmission node. The second resistor is coupled between a second output terminal and the second transmission node. The third resistor is coupled between a third output terminal and the first transmission node. The fourth resistor is coupled between a fourth output terminal and the second transmission node. The first, second, third, and fourth transistor groups are coupled to a first and a second reference voltages and electrically connected to the first, second, third, and fourth output terminals, respectively.