Detection circuit using a differential capacitive sensor with input-common-mode control in a sense interface
US9201090B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 2006 |
| Grant date | Dec 1, 2015 |
| Priority date | — |
| Expiry date | Aug 28, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P15/131
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A detection circuit is provided with a differential capacitive sensor and with an interface circuit having a first sense input and a second sense input, electrically connected to the differential capacitive sensor. Provided in the interface circuit are: a sense amplifier connected at input to the first sense input and to the second sense input and supplying an output signal related to a capacitive unbalancing of the differential capacitive sensor; and a common-mode control circuit, connected to the first sense input and to the second sense input and configured to control a common-mode electrical quantity present on the first sense input and on the second sense input. The common-mode control circuit is of a totally passive type and is provided with a capacitive circuit, which is substantially identical to an equivalent electrical circuit of the differential capacitive sensor and is driven with a driving signal in phase opposition with respect to a read signal supplied to the differential capacitive sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.