- 专利标题: High signal to noise ratio capacitive sensing analog front-end
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申请号: US13717780申请日: 2012-12-18
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公开(公告)号: US09389256B2公开(公告)日: 2016-07-12
- 发明人: Paolo Angelini , Giovanni Carlo Tripoli , Ernesto Lasalandra , Tommaso Ungaretti , Kien Beng Tan , Yannick Guedon , Dianbo Guo , Sze-Kwang Tan
- 申请人: STMicroelectronics Asia Pacific Pte. Ltd. , STMicroelectronics S.r.l.
- 申请人地址: SG Singapore IT Agrate Brianza (MI)
- 专利权人: STMicroelectronics Asia Pacific Pte Ltd,STMicroelectronics S.r.l.
- 当前专利权人: STMicroelectronics Asia Pacific Pte Ltd,STMicroelectronics S.r.l.
- 当前专利权人地址: SG Singapore IT Agrate Brianza (MI)
- 代理机构: Gardere Wynne Sewell LLP
- 主分类号: G06F3/044
- IPC分类号: G06F3/044 ; G01R27/26 ; G06F3/041
摘要:
Capacitance sensing circuits and methods are provided. The capacitance sensing circuit includes a capacitance-to-voltage converter configured to receive a signal from a capacitance to be sensed and to provide an output signal representative of the capacitance, an output chopper configured to convert the output signal of the capacitance-to-voltage converter to a sensed voltage representative of the capacitance to be sensed, an analog accumulator configured to accumulate sensed voltages during an accumulation period of NA sensing cycles and to provide an accumulated analog value, an amplifier configured to amplify the accumulated analog value, and an analog-to-digital converter configured to convert the amplified accumulated analog value to a digital value representative of the capacitance to be sensed. The analog accumulator may include a low pass filter having a frequency response to filter wideband noise.
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