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Screwdriver
Screwdriver is offline
#3
Feb23-12, 12:06 PM
P: 123
Do you have the datasheet for the LM741 opamp? (You should have it and refer to it as part of this lab work) Look for the plot of the Open Loop Gain & Phase response. Adding the external resistive negative feedback just sets the overall gain lower than the Open Loop Gain, up to the frequency where the Open Loop Gain approaches the Closed Loop Gain.
Thanks for the reply. Yes, I have that. I need a quantitative statement though; if there is no such thing I might just have to come up with some functions that approximate the Open-Loop curves.

You can also do some reading about "Dominant Pole Compensation" that is used inside opamps like the LM741:

http://www.analog.com/library/analog...2/appleng.html
This talked about a the "transfer function" of the amplifier a lot, which sounds promising, but it never actually said what it was.