A driving device includes a plurality of transmitters. Each transmitter includes a first current source, a second current source, a third current source, a fourth current source, a first switch, a second switch, a third switch, a fourth switch, a fifth switch, and a sixth switch. The first and the fourth switches are controlled by a first control signal. The second and the third switches are controlled by a second control signal. The second switch is coupled to the first switch. The third switch is coupled to the first current source. The fourth switch is coupled to the third switch and the second current source. The fifth and the sixth switches are controlled respectively by a third and a fourth control signal. The fifth switch is coupled to the third current source and the first switch. The sixth switch is coupled to the second switch and the fourth current source.