Accurate voltage comparator with voltage-to-current converters for both reference and input voltages
US6940318B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 6, 2003 |
| Grant date | Sep 6, 2005 |
| Priority date | — |
| Expiry date | Nov 4, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A stable voltage that is independent of supply voltage is applied to a pair of current sources. A first current source generates a first current that passes through a first resistor, setting a compare-in-put voltage. A source-input voltage is applied to the first current source to vary the first current and the compare-input voltage. A second current source generates a stable current that passes through a second resistor, setting a reference voltage. The compare-input voltage and the reference voltage are applied to inputs of a comparator that generates an output voltage that indicates when the source-input voltage causes the compare-input voltage to rise past the reference voltage. The first and second currents track each other over temperature and process variations and are independent of supply voltage. A more accurate comparison of the source-input voltage is thus made.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.