Automatic gain control circuit with high linearity and monotonically correlated offset voltage
US6538507B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 2002 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Feb 21, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45574
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An automatic gain control (AGC) circuit including a high gain amplifier, a feedback network and two transconductance amplifiers. The feedback network has a first end that receives an input signal of the AGC circuit, a second end coupled to the output of the high gain amplifier and two intermediate nodes. Each transconductance amplifier has an input coupled to a respective intermediate node of the feedback network and an output coupled to the input of the high gain amplifier. The transconductance amplifiers collectively control a position of a virtual ground within the feedback network to control gain of the AGC circuit. The transconductance amplifiers each include an attenuator and a transconductance stage coupled between the feedback network and the high gain amplifier and are configured to operate linearly across a relatively wide input voltage range. The input offset voltage of the AGC circuit varies monotonically with gain of the AGC circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.