Low voltage current reference circuit with active feedback for PLL
US5694033A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1996 |
| Grant date | Dec 2, 1997 |
| Priority date | — |
| Expiry date | Sep 6, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/262
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A current reference circuit includes a first, current mirror transistor having a gate coupled to a first feedback node, a source coupled to a first supply terminal and a drain forming a first reference node. A second, current mirror transistor has a gate coupled to the first feedback node, a source coupled to the first supply terminal and a drain forming a second reference node. A third transistor has a gate coupled to a second feedback node, a source coupled to a second supply terminal and a drain coupled to the first reference node. A fourth transistor has a gate coupled to the second feedback node, a source coupled to the second supply terminal and a drain coupled to the second reference node. A first operational amplifier has a first input coupled to the first reference node, a second input coupled to a bias node and an output forming the first feedback node. A second operational amplifier has a first input coupled to the second reference node, a second input coupled to the bias node and an output forming the second feedback node. The operational amplifiers are active elements which allow the current reference circuit to operate at a very low voltage and have a very low sensiti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.