active filter and GBW of amplifier

[akbarza]

hi
i downloaded the file Successful_Active_Filter_020713 (1).pptx before from net and i upload it here
my questions
1: in slidec 26, in the table is written that G=1 as condition. i think G is dc gain of opamp in closed loop unity configuaration.
is my guess right? which configuration(open loop or close loop) for opamp is used to create this pic?
2: it is seen that in definition of GBW is written GBW=Gain.BW and GBW=gain from 0db to AvoL.
I think AvoL is open loop gain of amplifier. is it true?
the draw belongs to open loop gain, but in left of it, this draw is used for closed loop bandwidth. is it true?
if yes,why in below of it has been said gain= closed loop voltage gain ?
3: the formula in slide 28, where does it come from and how do we proof it or extract it?
in mentioned formula, what is close-loop gain? namely is it dc gain of this section?
is GWB_section the open loop GBW of amplifier of each stage?
4: in slide 58, can anyone explain that how this formula can be derived?
thanks

 

[danadakk]

hi
i downloaded the file Successful_Active_Filter_020713 (1).pptx before from net and i upload it here
my questions
1: in slidec 26, in the table is written that G=1 as condition. i think G is dc gain of opamp in closed loop unity configuaration.
is my guess right? which configuration(open loop or close loop) for opamp is used to create this pic?
2: it is seen that in definition of GBW is written GBW=Gain.BW and GBW=gain from 0db to AvoL.
I think AvoL is open loop gain of amplifier. is it true?
the draw belongs to open loop gain, but in left of it, this draw is used for closed loop bandwidth. is it true?
if yes,why in below of it has been said gain= closed loop voltage gain ?
3: the formula in slide 28, where does it come from and how do we proof it or extract it?
in mentioned formula, what is close-loop gain? namely is it dc gain of this section?
is GWB_section the open loop GBW of amplifier of each stage?
4: in slide 58, can anyone explain that how this formula can be derived?
thanks

1) Its the G from of the amp configed as a NI follower out to -3 db, so its AC G = +1.

2) Avol is DC open loop G.

3) I believe its from classic second order f(s) for a network. So you can grind out
the algebra or use signal flow graph analysis to get at T(s) rapidly. The use
Q relationship definitions to sub/replace equation constants.

Q factor - Wikipedia

en.wikipedia.org

signal flow graphs at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

4) You would have to analyze a single stage, then apply pole shrinkage factor
to cascaded n filter. Or so I think.

http://rfic.eecs.berkeley.edu/ee242/pdf/Module_3_4_AmpsBroad.pdf

This will give you some general background -

https://hasler.ece.gatech.edu/Courses/ECE6414/Unit1/Discrete_01.pdf

Regards, Dana.