Capacitive sensing circuit for multi-touch panel, and multi-touch sensing device having same

A multi-touch sensing device comprising:

• a multi-touch panel in which a plurality of transmitting lines and a plurality of receiving lines are disposed;
• a transmitting circuit part connected to the transmitting line to supply a transmitting signal of a rectangular wave to the transmitting line;
• a receiving circuit part comprising a charge integrating circuit based on a current mirror integrating each charge in correspondence with a rising period and a falling period of the transmitting signal of the rectangular wave supplied from the transmitting circuit part, the receiving circuit part connected to a receiving line of the multi-touch panel to detect a difference of a capacitance generated between the transmitting line and the receiving line;
• a control signal generator outputting a first integral control signal and a second integral control signal that are mutually opposite to each other, the control signal generator
• (i) outputting the first integral control signal having an opposite phase to the transmitting signal and the second integral control signal having the same phase as the transmitting signal, so that the charge integrating circuit is operated in a first phase mode that a capacitance is decreased according to a touch,
• (ii) outputting the first integral control signal having the same phase as the transmitting signal and the second integral control signal having an opposite phase to the transmitting signal, so that the charge integrating circuit is operated in a second phase mode that a capacitance is increased according to a touch;
• and
• a touch determining part configured to determine whether or not a touch is generated based on a capacitance value detected in accordance with the first phase mode and a capacitance value detected in accordance with the second phase mode.