Patent ID: 9197207
Filing Date: 2015-11-24
Classification: G06F,H03K

Abstract:
1. A touch sensor circuit, comprising: a touch sensing capacitor, wherein a first terminal of the touch sensing capacitor produces a voltage according to a touching state thereon; a charging capacitor, serially connected between a detecting terminal and a reference voltage; a first current supplying unit, coupled to the detecting terminal, receiving a first bias voltage signal, and generating a first charging current at the detecting terminal according to the first bias voltage signal; a second current supplying unit, coupled to the detecting terminal, receiving a second bias voltage signal, and generating a second charging current at the detecting terminal according to the second bias voltage signal; and a switch unit, wherein a first terminal of the switch unit is coupled to the touch sensing capacitor, a second terminal and a third terminal of the touch sensing capacitor are respectively coupled to the first current supplying and the second current supplying unit, the first terminal of the switch unit is coupled to the second terminal or the third terminal according to a control signal, the second and third terminals of the switch unit respectively supply the first and second bias voltage signals; and a third transistor, having a first terminal, a second terminal and a control terminal, wherein the first terminal receives the reference voltage, the second terminal of the third transistor is coupled to the switch unit, and the control terminal of the third transistor is coupled to the second terminal of the third transistor; a fourth transistor, having a first terminal, a second terminal and a control terminal, wherein the first terminal receives the reference voltage, and the control terminal of the fourth transistor is coupled to the control terminal of the third transistor; a fifth transistor, having a first terminal, a second terminal and a control terminal, wherein the first terminal receives the power voltage, the second terminal of the fifth transistor is coupled to the second terminal of the fourth transistor, and the control terminal of the fifth transistor is coupled to the second terminal of the fifth transistor; and a sixth transistor, having a first terminal, a second terminal and a control terminal, wherein the first terminal receives the power voltage, second terminal of the sixth transistor is coupled to the detecting terminal, and the control terminal of the sixth transistor is coupled to the control terminal of the fifth transistor.