Amplifier with input referred common-mode adjustment
US5936469A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1997 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Aug 4, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45624
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit and method control the common-mode potential at an output (17, 18) of a fully differential amplifier (32) by feeding forward a common-mode correction signal through the amplifier. An input signal (V.sub.IN+ -V.sub.IN-) is amplified in the amplifier to produce a differential output signal (V.sub.O- -V.sub.O+) at the output. A common potential of the differential inputs (37, 38) of the amplifier is sensed with a transistor (54, 56) biased to a reference voltage (V.sub.CM) and amplified through the amplifier to produce a common-mode correction signal to offset a common-mode component of the differential output signal. A feedback circuit (33-36) is used to develop the common potential from the common-mode component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.