Digitally variable gain amplifier using multiplexed gain blocks
US7795974B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 2009 |
| Grant date | Sep 14, 2010 |
| Priority date | — |
| Expiry date | Apr 24, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/7239
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digitally variable gain amplifier comprising a front-end stage, a level shifter stage, and an output amplifier stage. The front-end stage comprises a high gain pre-amplifier and a low gain pre-amplifier driven in parallel by a differential input signal. A coarse gain control is realized by enabling only one pre-amplifiers at a time, while the differential input signal remains connected to the inputs of the disabled pre-amplifier. An attenuator following each pre-amplifier provides fine gain control. The enabled pre-amplifier amplifies the differential input signal and outputs a first dc voltage level. The disabled pre-amplifier is placed into a standby ready mode and outputs a second dc voltage level that is greater in magnitude than the first dc voltage level. The level shifter stage performs a minimum voltage selection operation to automatically select and level shift the amplified differential input signal, and further pass the signal to the output amplifier stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.