Differential amplifiers with current and resistance compensation elements for balanced output
US6369652B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 2000 |
| Grant date | Apr 9, 2002 |
| Priority date | — |
| Expiry date | May 15, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0812
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A differential amplifier has unequal resistance in its legs that compensates for an unequal current flow through the legs during a logic zero data input compared to logic one data input. The unequal resistance may be provided by adding a resistor in parallel to the leg that carries greater current during amplification, lowering the resistance in that leg and also the voltage that is output from that leg. Alternatively, a variable resistance may be provided to at least one of the legs to compensate for current inequalities between the legs. The variable resistance may be provided by a transistor that is controlled by a signal indicating process, voltage and/or temperature conditions of the amplifier and adjacent circuitry. Transistors may be employed in both legs as well as in a current source for the amplifier, providing balanced current regulation for the amplifier. Such current compensated differential amplifiers may be employed for various functions, for example as input receivers or delay elements in high frequency memory systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.