Variable gain current input amplifier and method
US7768351B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2008 |
| Grant date | Aug 3, 2010 |
| Priority date | — |
| Expiry date | Oct 21, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45674
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Variable gain circuitry includes a first input transistor (M1) having a source coupled to a first conductor (32), a gate coupled to a first input voltage (Vin+), and a drain coupled to a second conductor (30). An input of a first current mirror (M3,M4) is coupled to the second conductor to receive a current corresponding to the difference between the first input voltage and a second input voltage (Vin−). An output of the first current mirror is coupled to a source of current (M2). A first transistor (M5) has a gate coupled to a third conductor (31), a source coupled to a reference voltage (VSS), and a drain coupled to conduct output current (Iout). A second transistor (M6) and a resistive element (M7) are coupled in series between the third conductor and the first reference voltage (VSS), a gate of the second transistor being coupled to the third conductor to produce a nonlinear relationship between currents of the first transistor and the second transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.