Current feedback amplifier

[Junus2012]

Current feedback amplifiers as I read offer an incredible bandwidth that is not depending on the closed-loop gain, with a dynamic charasterictec that can not be defeated by voltage feedbak amplifiers, see for example the IC below.

https://www.ti.com/lit/ds/symlink/lmh6554.pdf?ts=1665474991603&ref_url=https%253A%252F%252Fwww.google.com%252F

My question, why most of the design still adhere to the voltage mode designs ?
and also I couldnt find a book to start basic design with it with CMOS technology

Thank you

 

[dick_freebird]

CFAs have an asymmetric front end and so deliver inferior DC accuracy. But they can't be beat, technology for technology, in high BW / slew applications.

 

[crutschow]

Current-feedback amplifiers perform well in wide bandwidth applications, but are generally inferior in more general op amp lower frequency AC and DC applications, so thus are mostly used only where high frequency operation is a requirement.

Current-feedback op amps use the current input transconductance characteristics of the BJT so don't know that there any are built with CMOS.

 

[KlausST]

Hi,

another drawback is:
due to the limited range of the feedback resistor value you are also limited in input resistor value.

Klaus

 

[danadakk]

Compound or composite amplifiers can get the best of both worlds.

https://www.edn.com/composite-amplifiers/

I cant seem to find an old ap note that showed a V OpAmp in a compound configuration
with an LM359.


Regards, Dana.

 

[kender]

I've compiled a list of application notes, book chapters, tutorials about circuit design with current-feedback op-amps

http://prolifictec.com/blog/2023/04/current-feedback-op-amps-reading-material.html

CFB, CFA

 

[Easy peasy]

the one you listed has an input Z of 19 ohm - still useful ?