Highest supply selection circuit
US7298181B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 2005 |
| Grant date | Nov 20, 2007 |
| Priority date | — |
| Expiry date | Dec 6, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/6871
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A power supply monitoring circuit that monitors and delivers the highest voltage power supply to an IC system includes a voltage comparator that receives two different power supply voltages, and outputs a first signal to the gate of a first switching transistor connected between a first power supply and an system power supply output node. The comparator output is also input to an inverter, the output of which comprises a second signal connected to the gate of a second switching transistor connected between a second power supply and the system power supply output node. When the first supply voltage exceeds the second supply voltage, the first transistor is switched on to connect the first supply to the system output node, and the second transistor is switched off; and vice versa. The comparator includes designed-in hysteresis to prevent simultaneous switching of the two transistors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.