Comparator circuit for differential swing comparison and common-mode voltage comparison
US6822435B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 24, 2002 |
| Grant date | Nov 23, 2004 |
| Priority date | — |
| Expiry date | Mar 17, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/31932
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A comparator circuit includes at least one transconductance stage that receives two test voltages and two reference voltages. The transconductance stage produces two test currents that are proportional to the test voltages and two reference currents. A switching circuit is coupled to the transconductance stage. The switching circuit has two output terminals that are coupled to a conventional comparator stage. The switching circuit can combine the test currents with the reference currents to realize a differential swing comparison mode and a common-mode comparison mode as required for testing differential signals. Moreover, by disabling appropriate output signals from the at least one transconductance stage, a single-ended comparison mode is realized. By using two identical transconductance amplifiers, the non-linearity of the transconductance stage is advantageously canceled out.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.