A sense signal is continuously received from a capacitive touch-sensing panel. A reference signal is set or adjusted to have a level of the sense signal be in a first relation to that of the reference signal in an initial state, and the sense signal is compared with the reference signal to generate a comparison signal in a sensing state. The comparison signal is outputted with a first logic level when a level of the sense signal is in the first relation to a level of the reference signal, and outputted with a second logic level when a level of the sense signal is in a second relation to a level of the reference signal. Whether a touch action is conducted is determined according to a compared result of occurrences of the first and second logic levels of the comparison signal generated within a preset time period.