Fingerprint sensing system with sensing reference potential providing circuitry
US9953204B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 2017 |
| Grant date | Apr 24, 2018 |
| Priority date | — |
| Expiry date | Jan 5, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/076
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A fingerprint sensing system comprising a device connection interface including a device reference potential input, a sensing arrangement, and sensing reference potential providing circuitry. The sensing arrangement includes multiple sensing structures and read-out circuitry connected to each of the sensing structures. The sensing reference potential providing circuitry provides a sensing reference potential to the sensing arrangement in the form of a sensing reference signal alternating between a first sensing reference potential and a second sensing reference potential, and comprises a first capacitor; a second capacitor; charging circuitry; and switching circuitry for alternatingly switching the sensing reference potential providing circuitry between a first state in which the first capacitor and the second capacitor are connected in parallel to the charging circuitry; and a second state in which the first capacitor and the second capacitor, when charged, are connected in series between the device reference potential input and the sensing arrangement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.