发明名称 |
CAPACITANCE MEASUREMENT |
摘要 |
<p>A differential amplifier has an output and differential first and second inputs. A switch disposed between a sensor electrode and the second input is opened to initiate a reset phase where the sensor electrode and the differential amplifier are decoupled. A feedback capacitance disposed between the second input and the output is reset to a first level of charge. The switch is closed to initiate a measurement phase where the second input and sensor electrode are coupled. In the measurement phase: charge is balanced between the sensor electrode and the feedback capacitance such that a sensor electrode voltage equals a voltage of the first input equals a voltage of the second input, and the sensor electrode is charged; and the differential amplifier is utilized to integrate charge on the sensor electrode, such that an absolute capacitance is measured.</p> |
申请公布号 |
WO2014014785(A1) |
申请公布日期 |
2014.01.23 |
申请号 |
WO2013US50386 |
申请日期 |
2013.07.12 |
申请人 |
SYNAPTICS INCORPORATED |
发明人 |
SHAHROKHI, FARZANEH;SCHWARTZ, ADAM;SHAHPARNIA, SHAHROOZ;REYNOLDS, JOSEPH KURTH;DATTALO, TRACY SCOTT |
分类号 |
G06F3/041;G01R27/26;G06F3/044 |
主分类号 |
G06F3/041 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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