Differential amplifiers with enhanced gain and controlled common-mode output level
US7138865B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2005 |
| Grant date | Nov 21, 2006 |
| Priority date | — |
| Expiry date | Oct 4, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/45659
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Differential amplifiers are provided with a common-mode controller that establishes an amplifier common-mode output level while it also enhances amplifier gain and output impedance. The amplifier includes cascode transistors and the controller includes positive-feedback transistors that respond to an output side of the cascode transistors and negative-feedback transistors that respond to an input side of the cascode transistors. Gain and output impedance are increased by the positive-feedback transistors and the increase is controlled by the negative-feedback transistors. Common-mode level is established by voltages between current and control terminals of the positive-feedback transistors. The differential amplifiers are shown to be especially suited for use in switched-capacitor structures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.