Highly accurate synchronized charge pump for capacitive touch screen system
US10747382B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 2018 |
| Grant date | Aug 18, 2020 |
| Priority date | — |
| Expiry date | Oct 29, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0003
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed herein is a touch screen controller including a driver circuit applying a drive signal to a drive line of a capacitive touch sensing panel. The driver circuit is powered by an accurate supply voltage. A driver supply circuit receives an input supply voltage and outputs the accurate supply voltage. The driver supply circuit includes a clocked comparator comparing a divided version of the accurate supply voltage to a reference voltage and outputting a comparison signal based thereupon. A voltage control circuit (e.g. a charge pump circuit) generates the accurate supply voltage in response to the comparison signal. The clocked comparator and voltage control circuit are both clocked by a driver supply circuit clock.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.