Power supply interruption detection and response system for a microcontroller
US5428252A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1992 |
| Grant date | Jun 27, 1995 |
| Priority date | — |
| Expiry date | Jan 3, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY04S20/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A microcontroller power management system wherein the voltage of a power supply is monitored and the microcontroller central processing unit ("CPU") receives an interrupt signal when the supply voltage falls below a predetermined level. The CPU monitors the duration of the low voltage condition and switches into a sleep mode, after storing any data in its registers that are not maintained in the sleep mode, when that duration exceeds a fixed limit that indicates more than a temporary power glitch is being experienced. If only a short power glitch, the CPU continues normal operation. A large capacitor connected to the power supply input to the microcontroller provides enough energy for the microcontroller to operate normally during short glitches and to operate in a sleep mode for a considerable time, thereby maintaining data in CMOS static RAM until power is restored. This is particularly useful for battery operated systems, responding to both a low battery voltage condition and to a complete loss of power during battery replacement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.