Fully balanced transimpedance amplifier for high speed and low voltage applications
US6433638B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 2000 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Sep 6, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45711
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A fully balanced transimpedance amplifier for high speed and low voltage applications is provided. An input stage of the amplifier uses a matched pair of common source connected transistors with sources tied directly to ground to eliminate the Vds overhead usually found in differential pairs. The ground connection minimizes a source resistance noise component, while matching minimizes power supply noise generation and susceptibility for an array of amplifiers. Feedback resistors along with diode connected MESFETS determine the transimpedance of the amplifier. The nonlinearity of diodes helps to soften clipping. Transresistance also determined the noise generated by the amplifier, and the diode connected MESFETS offer lower noise than resistors for the same impedance. Stability is achieved through use of only a single stage of gain in a loop of the input stage, while additional gain is achieved through cascading in the input stage. A differential stage minimizes any difference in amplitude between two sides of the amplifier input stage. Two stages of source followers provide buffering to drive a relatively low impedance load at the output of the amplifier. Single integrated capacito…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.