Active feedforward interference cancellation techniques for sensor analog front-end
US10503320B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 2017 |
| Grant date | Dec 10, 2019 |
| Priority date | — |
| Expiry date | May 12, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0446
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Embodiments herein provide input devices that include a display panel on which a discrete capacitive sensor is disposed to form a capacitive sensing region. The capacitive sensor includes a plurality of sensor electrodes that are used to generate capacitive sensing signals indicating user interaction with the input device. Moreover, the input device includes analog interference detection circuitry for mitigating the negative impact of display noise on capacitive sensing. In one embodiment, the input device includes a reference circuit which is capacitively coupled to a display noise source and outputs a reference voltage that biases a charge integrator in a receiver channel used for capacitive sensing. In another embodiment, the input device includes a current conveyor coupled to an idle transmitter electrode of the sensor electrodes which outputs a correction current to a receiver channel to cancel a display noise current injected into the receiver channel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.