Method and apparatus for power supply switching with logic integrity protection
US5790873A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 1996 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | Jul 23, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY04S20/20
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for providing power management functions in a computer or other electronic system which includes a primary power supply, a trickle power supply and a battery back-up power supply. A power management circuit includes a storage element which stores an indication of the current turn-on or turn-off condition of the primary power supply. The power management circuit also includes a group of logic gates which process signals which are supplied to the storage element under normal operating conditions to control the turn-on or turn-off condition of the primary power supply. The power management circuit senses when the trickle supply is deactivated due to a line power failure or the like, and subsequently switches the power supply inputs of the storage element and certain of the logic gates from the trickle supply to the battery back-up supply. A blocking signal is generated which prevents those signals which require the trickle supply for logic integrity from being applied to the storage element. In this manner, only signals which do not require the trickle supply for logic integrity are applied to the storage element while the trickle supply is deactivated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.