发明公开
- 专利标题: DC RESTORE SCHEME FOR CAPACITIVE SENSING AMPLIFIERS WITH OPTIMAL NOISE FILTERING
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申请号: US18070081申请日: 2022-11-28
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公开(公告)号: US20240186971A1公开(公告)日: 2024-06-06
- 发明人: Luca Collamati , Federico Mazzarella
- 申请人: InvenSense, Inc.
- 申请人地址: US CA San Jose
- 专利权人: InvenSense, Inc.
- 当前专利权人: InvenSense, Inc.
- 当前专利权人地址: US CA San Jose
- 主分类号: H03F3/70
- IPC分类号: H03F3/70 ; G01D5/24 ; G01P15/125 ; G01P15/14
摘要:
A capacitive sensing charge amplifier, e.g., in a direct current (DC) feedback network, may incorporate a switching capacitor, including a first control switch and a second control switch, which receives a switching signal to charge and discharges the switching signal to a virtual ground of a sense amplifier. Noise incorporated into the output of the sense amplifier (e.g., a MEMS output signal) is filtered by a demodulation signal at a demodulator such that the period average noise at the demodulator output equals zero. The time varying nature of the switching capacitor resistance generally reshapes the system's post-demodulation noise to reduce its low frequency output noise.
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