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.

negative feedback and loop gain problem

Status
Not open for further replies.

Elhossiny

Newbie
Joined
Feb 14, 2022
Messages
4
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
30
273917950_677385456779064_7355693254710850813_n.png

I have a problem in this circuit when I simulate its loop gain on cadence
the open-loop gain decreased and open-loop BW increased and GBW remain constant
 

Attachments

  • 273473258_243146664701387_2501118764922879138_n.jpg
    273473258_243146664701387_2501118764922879138_n.jpg
    37.2 KB · Views: 89

I have a problem in this circuit when I simulate its loop gain on cadence
the open-loop gain decreased and open-loop BW increased and GBW remain constant

I don`t understand the meaning of this sentence.
What do you mean with "open.loop gain"? Is it the gain of the opamp without feedback?
Why do you speak about the "open-loop gain" while simulating the "loop gain"?
More than that - "decreased" in comparison to which other gain?
 

i expect the LG= Aol(first stage)*Aol(second stage), and BW limited to OTA BW.
when i simulate i found that LG= Aol(first stage only) and BW= BWota *(Aol second stage "common source).
 

i expect the LG= Aol(first stage)*Aol(second stage), and BW limited to OTA BW.
when i simulate i found that LG= Aol(first stage only) and BW= BWota *(Aol second stage "common source).
How did you simulate the loop gain? Did you take care of the correct bias points?
More than that - the diagram shows an opamp, but you always are speaking about an OTA.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top