Common mode rail-to-rail amplifier with a constant transconductance
US5729177A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 18, 1995 |
| Grant date | Mar 17, 1998 |
| Priority date | — |
| Expiry date | Dec 18, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45302
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An amplifier includes two complementary differential input stages and a first current source that is switched as a function of the input voltage of the amplifier in order to render active one or the other of the input stages by establishing the quiescent current of the input stage. A folded cascode stage has two cascode transistors whose currents are determined by a bias voltage of these transistors and reduced by the currents circulating in the output branches of a first of the differential input stages. Circuitry switched at the same time as the first current source for maintaining a constant current in the cascode transistors when one of the differential stages changes between an active state and an inactive state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.