Journal article
Feedback analysis of transimpedance operational amplifier circuits
The transimpedance or current feedback operational amplifier (CFB op-amp) is reviewed and compared to a conventional voltage mode op-amp using an analysis emphasizing the basic feedback characteristics of the circuit. With this approach the paradox of the constant bandwidth obtained from CFB op-amps is explained.
It is demonstrated in a simple manner that the constant gain-bandwidth product of the conventional op-amp and the constant bandwidth of the CFB op-amp are both in accordance with basic feedback theory and that the differences between the traditional op-amp and the CFB op-amp are due to different ways of controlling the closed-loop gain.
For the traditional op-amp the closed-loop gain is altered by altering the loop gain, whereas the closed-loop gain in a CFB op-amp configuration is altered by altering the input attenuation to the feedback loop while maintaining a constant-loop gain
| Language: | English |
|---|---|
| Publisher: | IEEE |
| Year: | 1993 |
| Pages: | 275-278 |
| ISSN: | 15581268 , 10577122 , 15580806 and 15498328 |
| Types: | Journal article |
| DOI: | 10.1109/81.224302 |
| ORCIDs: | Bruun, Erik |
Attenuation Bandwidth Equations Feedback circuits Feedback loop Flow graphs Frequency Operational amplifiers Predistortion Voltage closed-loop gain constant-loop gain current feedback operational amplifier feedback feedback characteristics gain-bandwidth product input attenuation network analysis operational amplifiers transimpedance operational amplifier circuits
