The application discloses a touch controller to determine a position where a user touches a touchscreen. The touchscreen includes a first transmitting electrode, a second transmitting electrode and a receiving electrode. The touch controller includes a signal generation module and a demodulation module. The signal generation module is configured to perform an in-phase code transmission at a first time so that the receiving electrode receives an in-phase code receiving signal correspondingly, and perform an inverting-phase code transmission at a second time so that the receiving electrode receives an inverting-phase code receiving signal correspondingly. The demodulation module is configured to determine the position where the user touches the touchscreen according to the in-phase code receiving signal corresponding to the first time and the inverting-phase code receiving signal corresponding to the second time.