| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a sensing circuit for a capacitance type touch panel, generating a large voltage drop at an output terminal of the sensing circuit. <P>SOLUTION: The sensing circuit includes an operational amplifier, first-sixth switches, and first and second feedback capacitors. The operational amplifier has a positive side input terminal, a negative side input terminal, and the output terminal, and a reference voltage is input to the positive side input terminal. The first switch is connected between a reception electrode and the negative side input terminal, and the second switch is connected between the negative input terminal and the output terminal. The third switch is connected to the negative side input terminal and the first feedback capacitor, and the fourth switch is connected to the first feedback capacitor and the output terminal. The fifth switch is connected to the negative side input terminal and the second feedback capacitor, and the sixth switch is connected to the second feedback capacitor and the output terminal. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
