Ultra-low power wakeup circuit device
US8988254B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 2013 |
| Grant date | Mar 24, 2015 |
| Priority date | — |
| Expiry date | Nov 5, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M11/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An ultra-low power wakeup circuit device includes a keyboard, a key scan circuit, a storage unit, and a comparator unit. The key scan circuit sequentially outputs scanning signals from the first scan line to N-th scan line for acquiring N key scan data. The key scan circuit performs an XOR operation on the N key scan data to generate a current key scan data. The storage unit is connected to the key scan circuit for receiving the current key scan data and storing the current key scan data as a previous key scan data. The comparator unit is connected to the key scan circuit and the storage unit for comparing the current key scan data with the previous key scan data. When the current key scan data is different from the previous key scan data, the comparator unit generates a wakeup signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.