Capacitance to code converter with sigma-delta modulator
US9166621B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 13, 2013 |
| Grant date | Oct 20, 2015 |
| Priority date | — |
| Expiry date | Jun 13, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M11/02
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method of converting a capacitance measured on a sensor element to a digital value. The apparatus may include a matrix-scanning device including drive lines and sense lines. A sense element is located at an intersection of one of the drive lines and one of the sense lines. The apparatus also includes a modulation circuit coupled to the drive lines and the sense lines, and a switching circuit having first switches controlled by a clock. The modulation circuit is configured to measure a mutual capacitance on the sense element and to convert the measured mutual capacitance to a first digital value. The modulation circuit is configured to measure a self-capacitance on at least one of the drive lines and to convert the measured self-capacitance to a second digital value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.