Patent ID: 7764200
Filing Date: 2010-07-27
Classification: H03K

Abstract:
1. A capacitive button device, comprising: a signal input unit for inputting a voltage signal; a first amplifier having a positive input terminal coupled to the signal input unit to receive the voltage signal and a negative input terminal coupled to a reference voltage; a first switching unit having an input terminal coupled to an output terminal of the first amplifier; a second amplifier having a negative input terminal coupled to an output terminal of the first switching unit; a second switching unit having an input terminal coupled to another output terminal of the first switching unit and another input terminal coupled to an output terminal of the second amplifier; an analog-to-digital converting unit having an input terminal coupled to an output terminal of the second switching unit; a third switching unit having an input terminal coupled to an output terminal of the analog-to-digital converting unit; a data output unit coupled to an output terminal of the third switching unit; a data storage unit having an input terminal coupled to another output terminal of the third switching unit; and a digital-to-analog converting unit having an input terminal coupled to an output terminal of the data storage unit and an output terminal coupled to a positive input terminal of the second amplifier.