Precision automatic gain control circuit
US6763228B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2001 |
| Grant date | Jul 13, 2004 |
| Priority date | — |
| Expiry date | Dec 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G7/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An automatic gain control (AGC) amplifier including a high gain transimpedance amplifier, a resistive feedback network and multiple transconductance stages coupled in the feedback path of the AGC amplifier. The feedback network receives an input signal and is coupled to the output of the high gain amplifier and has multiple intermediate nodes. Each transconductance stage has an input coupled to an intermediate node of the feedback network and an output coupled to the input of the high gain amplifier. Each transconductance stage is independently controllable to position a virtual ground within the feedback network to control closed loop gain. Each transconductance stage may have a bias current input coupled to a bias current control circuit. The control circuit controls each bias current to vary the gain of the AGC amplifier. The bias currents may be linearly controlled employing a ramp function to achieve a linear in dB gain response.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.