Proximity detection circuit and method of detecting capacitance changes
US7102366B2 · kind B2 · utility
33Cited by
100References
46Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 20, 2004 |
| Grant date | Sep 5, 2006 |
| Priority date | — |
| Expiry date | Feb 20, 2024 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA47K2010/3668
- WIPO fieldFurniture, games
- WIPO sectorOther fields
Abstract
A proximity detection circuit. An oscillator circuit is adapted to provide charge to an antenna. An operational amplifier, operated as a unity gain follower, receives an antenna signal which is representative of an external capacitive load on the antenna. A detector circuit receives the antenna signal via the operational amplifier and outputs a detection signal in response to changes in the antenna signal. A comparator receives the detection signal and is adapted to generate an output signal in response thereto.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.