Capacitance-to-voltage interface circuits
US8766650B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 2012 |
| Grant date | Jul 1, 2014 |
| Priority date | — |
| Expiry date | Jun 2, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/2605
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.