发明授权
- 专利标题: Capacitance-to-voltage interface circuits
- 专利标题(中): 电容电压接口电路
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申请号: US13344415申请日: 2012-01-05
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公开(公告)号: US08766650B2公开(公告)日: 2014-07-01
- 发明人: Ashish Khanna , Sung Jin Jo
- 申请人: Ashish Khanna , Sung Jin Jo
- 申请人地址: US TX Austin
- 专利权人: Freescale Semiconductor, Inc.
- 当前专利权人: Freescale Semiconductor, Inc.
- 当前专利权人地址: US TX Austin
- 代理机构: Ingrassia Fisher & Lorenz, P.C.
- 主分类号: G01R27/26
- IPC分类号: G01R27/26
摘要:
A capacitance-to-voltage interface circuit is utilized to obtain a voltage corresponding to a detected capacitance differential, which may be associated with the operation of a capacitive sensing cell. The interface circuit includes a capacitive sensing cell, an operational amplifier adapted for selective coupling to the capacitive sensing cell, a feedback capacitor for the operational amplifier, a load capacitor for the operational amplifier, and a switching architecture associated with the capacitive sensing cell, the operational amplifier, the feedback capacitor, and the load capacitor. During use, the switching architecture reconfigures the capacitance-to-voltage interface circuit for operation in a plurality of different phases. The different operational phases enable the single operational amplifier to be used for both capacitance-to-voltage conversion and voltage amplification.
公开/授权文献
- US20120105079A1 CAPACITANCE-TO-VOLTAGE INTERFACE CIRCUITS 公开/授权日:2012-05-03
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