[TOUCH PAD AND POSITION DETECTING CIRCUIT AND METHOD THEREOF]

A touch pad and a position detecting circuit and method thereof are provided. The touch pad uses a waveform generator to generate an input signal; the input signal is capable of gradually moving a position of a zero voltage on the sensing pad in a predetermined direction. The touch pad also uses the zero voltage detector to detect when a zero voltage of the sensing signal of the sensing pen occurs so as to determine the position of the sensing pen on the sensing pad. Hence, the analog-to-digital converter is not required. Therefore, the resolution can be easily expanded, and the cost, the preciseness, and the specification can be easily controlled.