Self-capacitor sensing using alternating-current-mode bridge with global current rotation for capacitive touch panels
US11954287B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 2023 |
| Grant date | Apr 9, 2024 |
| Priority date | — |
| Expiry date | Apr 24, 2043 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0446
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques are described for using a multi-branch AC-mode bridge approach with global current rotation for self-capacitor sensing in a capacitive touch panel, such as integrated into a display of a touchscreen electronic device. K channels are coupled with K branches of a multi-branch AC-mode bridge to form K−1 pairs of channels for concurrent differential readout. K nominally identical sinusoidal input currents are generated based on an error signal, which is generated based on comparing a sinusoidal driver signal with feedback from one or more of the K branches. A unit current rotator rotates the K sinusoidal input currents to each of the branches, so that each branch current is formed by a rotating contribution from each of the sinusoidal input currents. Driving each branch with its branch current manifests a respective branch voltage, and differences between the branch voltages can be used to differentially sense pairs of channels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.