Patent ID: 8624852

Claim:
A semiconductor device comprising: a plurality of first terminals connected to a plurality of touch electrodes, respectively; a second terminal connected via a capacitor to a line of a reference voltage; a switch circuit for connecting, to a predetermined node, one of said plurality of first terminals that is associated with a touch electrode selected from said plurality of touch electrodes; and a charging and discharging circuit for performing a charging operation of charging said capacitor, a discharging operation of releasing a charge of said selected touch electrode, and a distributing operation of distributing a charge of said capacitor via said predetermined node to said selected touch electrode, whether said selected touch electrode is touched by a human body being determined based on a voltage of said predetermined node; the semiconductor device further comprising: a third terminal connected via a resistor element to said second terminal; and a fourth terminal connected via a sub capacitor to said third terminal and connected to said predetermined node, wherein said charging and discharging circuit in said charging operation charges said capacitor by applying a first voltage to said second terminal and said predetermined node, said charging and discharging circuit in said discharging operation releases a charge of said sub capacitor and a charge of said selected touch electrode by applying a second voltage lower than said first voltage to said third terminal and said fourth terminal, and said charging and discharging circuit in said distributing operation distributes a charge of said capacitor to said selected touch electrode via said resistor element, said sub capacitor and said predetermined node by setting said first to third terminals in a high-impedance state.