so you thought you knew op-amp theory?

[unclejed613]

**broken link removed**

very interesting reading about real-world op amp behavior vs what the textbook says...

 

[tvtech]

That's just another reason why I dig ETO The learning curve never stops.

Thank's unclejed613. More stuff for me to think about

Cheers,
TV Tech

 

[MrAl]

Hi,

Ever since i found out about op amp slew rate i had always thought about there being a theoretical integrator inside, so that's nothing new to me.

The "Virtual Ground" concept is still a good concept and simplifies many problems, however i do find that newcomers get confused when they are told that the point of V.G. actually *changes* level during normal operation. I think they get the idea from the phrase that is stays constant and is always at 0.000000v.
In fact, it varies with the gain.

Good point about the gain vs frequency when it's used at some significant frequency level. Its gain starts out very high, but rolls off. The nice thing is through that the DC gain is still high and that's often just as important as knowing that the AC gain rolls off.

 

[BrownOut]

Good article, but I have to agree with the commenter who wrote this:

It seems most of these "myths" you mention are those of poor designers that you've met who forget to include things like finite bandwidth into their calculations. I rarely meet good designers who think an op amp has anything "infinite". I'm wondering who your audience was.

Also, there were some mathimatical erroes, pointed out in the comments section.