Transconductance amplifier with a filter for rejecting noise outside the useful band
US8035422B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 15, 2008 |
| Grant date | Oct 11, 2011 |
| Priority date | — |
| Expiry date | Jan 15, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45652
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention relates to a transconductance amplifier, providing current variations di=k·dv when it receives voltage variations dv.The amplifier comprises a first MOS transistor (MN4) whose drain provides differential currents (I−di, I+di). It comprises an output stage having a second transistor (MP5) of a type opposite to the first, whose source is linked to the drain of the first, whose gate is biased at a constant potential (Vref), and whose drain receives the current variations which are provided by the first transistor and which must be applied to a sampling capacitor. The amplifier furthermore comprises a filter (FLT) with frequency response centered on the central frequency Fo of the signals to be converted, having a very high impedance around this central frequency and a low impedance outside the useful spectrum, the filter being connected to the source of the second transistor (MP5) so as to divert away from the second transistor the current variations which are in a frequency band situated outside the useful spectrum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.