Adjustable resistance
US7940077B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 19, 2006 |
| Grant date | May 10, 2011 |
| Priority date | — |
| Expiry date | Nov 6, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/66
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In one implementation, a termination circuit may include a variable resistance circuit that comprises a resistance network in which the resistance of a parallel combination of two complementary transistors of opposite types is substantially independent of the drain-to-source voltages of the transistors when the gate-to-source voltages of the transistors are substantially equal in magnitude and opposite in sign. In various examples, the network may include a resistor in parallel and/or series with the transistors. Some implementations may adjust a resistance of the network in response to a digital-to-analog converter output signal. In another implementation, an integrated circuit may include a termination stage with an integrated resistor in parallel or series with a circuit having a tunable impedance. In an illustrative embodiment, relative channel width of the first and second transistors may be selected to realize substantially complementary characteristics for drain-to-source voltage vs. drain-to-source resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.