Invention Grant
- Patent Title: Capacitive sensing analog front end
- Patent Title (中): 电容式感应模拟前端
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Application No.: US12972159Application Date: 2010-12-17
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Publication No.: US09244569B2Publication Date: 2016-01-26
- Inventor: Yannick Guedon , Kien Beng Tan , Kusuma Adi Ningrat , Dianbo Guo
- Applicant: Yannick Guedon , Kien Beng Tan , Kusuma Adi Ningrat , Dianbo Guo
- Applicant Address: SG Singapore
- Assignee: STMicroelectronics Asia Pacific Pte Ltd
- Current Assignee: STMicroelectronics Asia Pacific Pte Ltd
- Current Assignee Address: SG Singapore
- Agency: Gardere Wynne Sewell LLP
- Main IPC: G06F3/045
- IPC: G06F3/045 ; G06F3/044

Abstract:
A capacitive sensing analog front end for a touchscreen system having an improved signal-to-noise ratio includes a capacitance-to-voltage converter having an input for coupling to an external sampling capacitor, a summer having a first input coupled to an output of the capacitance-to-voltage converter, a low pass filter having an input coupled to an output of the summer and an output for providing an output signal; and a sample-and-hold circuit having an input coupled to the output of the low pass filter and an output coupled to a second input of the summer. The signal-to-noise ratio of the touchscreen system is improved by extracting the DC shift of a touch signal during a monitoring period and then subtracting the DC shift before integrating the touch signal.
Public/Granted literature
- US20110242048A1 CAPACITIVE SENSING ANALOG FRONT END Public/Granted day:2011-10-06
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