Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

opamp AC test with Bipolar input

Status
Not open for further replies.
N

naisare

Member level 2
Joined
Oct 18, 2004
Messages
43
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,288
Activity points
391
Hi,
I want to test the ac analysis of opamp with Bipolar input stages.
I used the big R and big C in the feedback loop to open the feedback for AC analysis.This works only for the CMOS input stages. But bipolar input stages need base currents..
Can anyone help me with the test circuit?

Thank you..
 

I suppose you want do simulate the LOOP GAIN, don´t you ?
I suggest to place an ac source between opamp output (out) and the feedback path (in); thus the dc bias point is preserved and you can do the ac analysis.
The loop gain then is simply V(out)/V(in).
This method has only a very small loading error, however, as the opamp output resistance is low and if the feedback path has a higher resistance at least by a factor of 10, the error can be neglected. In any case this method is better than the "big L and big C" method.
 

which kind of analysis u want to do????u wana analyse ic package,if yes,then just check out two things
1 check it in open loop configuration
2 check it in unity follower configuration
anyways whats u want to do
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top