Common mode output current control circuit and method
US6538513B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 2001 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Dec 3, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/4565
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An amplifier with common mode output control including a reference circuit, a current mirror input circuit, a differential current mirror, a summing junction, first and second feedback amplifiers, first and second feedback current mirrors, and a differential output circuit. The input circuit receives the differential input voltage and develops a differential input current having polarity currents that have a constant sum based on a reference signal. The differential current mirror mirrors the differential input current into first and second high impedance nodes. The feedback amplifiers and the feedback current mirrors generate feedback current into the high impedance nodes in response to variations of summing junction voltage and maintain a constant common mode current. The output circuit develops a differential output current based on the differential input current mirrored into the high impedance nodes. RC compensation is provided to compensate open loop gain and the common mode output current loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.