Variable gain amplifier with improved power supply noise rejection
US9680418B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 2015 |
| Grant date | Jun 13, 2017 |
| Priority date | — |
| Expiry date | Nov 13, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45494
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A voltage gain amplifier (VGA) configured to have reduced supply noise. The VGA includes first resistor, first FET, and a first current-source coupled between first and second voltage rails. The VGA includes second resistor, second FET, and second current-source coupled between the voltage rails. A variable resistor is coupled between the respective sources of the first and second FETs. Variable capacitors are coupled between the first or a third voltage rail and the sources of the first and second input FETs, respectively. If capacitors are coupled to the first voltage rail, noise cancellation occurs across the gate-to-source voltages of the FETs if an input differential signal applied to the gates of the FETs is derived from a supply voltage at the first voltage rail. If capacitors are coupled to the third rail, supply noise is reduced if the supply voltage at the third rail is generated by a cleaner regulator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.