Video Op-Amps

Discussion of modular and standalone video generating/processing techniques and associated hardware.

Moderators: luketeaford, Joe., lisa, Kent, daverj

Post Reply
User avatar
fletch
Common Wiggler
Posts: 144
Joined: Tue Jul 05, 2011 2:29 pm
Location: Oakland, CA

Video Op-Amps

Post by fletch » Sun Aug 28, 2011 11:51 pm

I'm wondering which are some of the better op-amps out there for video. Right now I'm comparing the LM6172 and the AD8072, they have the same bandwidth but the former is a voltage feedback op-amp and the latter is current feedback. Are both types useful for video in different applications?

I also read elsewhere that there's better selection in the SMT variety, so I would be interested in hearing what some of the better ones are in either DIP or SMT.

User avatar
lizlarsen
Super Deluxe Wiggler
Posts: 2155
Joined: Wed Jan 13, 2010 1:45 pm
Location: Denton, TX

Post by lizlarsen » Mon Aug 29, 2011 11:25 am

There have been a few threads on this, here is one:
viewtopic.php?t=25814

User avatar
daverj
Vintage Video Wiggler
Posts: 8514
Joined: Fri Jun 19, 2009 11:09 am

Post by daverj » Mon Aug 29, 2011 2:13 pm

Voltage feedback and current feedback are both useful in video. They have different advantages and disadvantages. In some circuits they can work the same, but in other cases there are distinct advantages to each.

Without getting too technical, a voltage feedback amp is generally easier to design with and is more stable in a wide range of circuit designs. Current feedback circuits can get unstable in certain configurations, but can pass higher frequencies in other configurations. On the other hand, voltage feedback amps are now available with very high bandwidth and that reduces the number of places where a current feedback amp is needed.

Unless you really study how to use current feedback amps, you'll probably have better results sticking to voltage feedback amps.

Post Reply

Return to “Video Synthesis”