On-chip detection circuit off-chip mechanical switch's open and close actions
US7406339B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 2002 |
| Grant date | Jul 29, 2008 |
| Priority date | — |
| Expiry date | Apr 23, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/6041
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An on-chip detection circuit automatically detects when an external switch has been activated. When the device is initialized, the detection circuit measures the operating current and coverts the information into an analog voltage. The analog voltage is then processed through an on-chip analog-to-digital converter and the digitized result is stored as a reference value. To sense the open and close action of the off-chip mechanical switch, the device then takes a sample of the operating current periodically, digitizes this information and compares the sampled value to the reference value. A change in value larger than some predetermined level indicates the external switch has been activated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.