Backup battery switching circuitry for a microcomputer or a microprocessor
US4908790A · kind A · utility
65Cited by
7References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1988 |
| Grant date | Mar 13, 1990 |
| Priority date | — |
| Expiry date | Mar 10, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/30
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Backup battery switching circuitry for a microcomputer or a microprocessor includes circuitry for selectively coupling a backup battery to a power supply output terminal of the microcomputer or microprocessor for powering an external circuit such as a static RAM. The backup battery voltage is normally coupled to the power supply output terminal in the absence of a primary power source, but may be isolated from the power supply output terminal when a predetermined voltage is applied to a logic input pin and a predetermined sequence of events is executed by the microcomputer or microprocessor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.