System and method for sensing capacitance change of a capacitive sensor
US7339384B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 2006 |
| Grant date | Mar 4, 2008 |
| Priority date | — |
| Expiry date | Jun 2, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K7/34
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to systems and methods for sensing capacitance change of a capacitive sensor and for optimizing a capacitive sensing circuit. In an exemplary embodiment, a capacitive sensor may be coupled to an amplifier at floating node. A programming circuit is connected to the floating node for controlling a charge on the floating node. A method of controlling the charge of the floating node is also provided. The method includes applying a first predetermined voltage to a source of a programming transistor, applying a second predetermined voltage to a floating gate of the programming transistor, and applying a third predetermined voltage to a drain of the programming transistor until a charge on the floating gate of the programming transistor reaches a predetermined value. The charge on the floating gate of the programming transistor drives the charge on the floating node to the predetermined value, and thus is controlled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.