The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
May 20th, 2019, 9:53am
Pages: 1
Send Topic Print
CMFB loop bandwidth requirement for differential amplifier (Read 152 times)
Salim2019
New Member
*
Offline



Posts: 5

CMFB loop bandwidth requirement for differential amplifier
Mar 15th, 2019, 4:15pm
 
Dear friends,
I am designing fully differential amplifier and now I would like to know please what is the relationship between the CMFB loop frequency and the differential signal frequency.

can I CMFB loop with frequency less than the differential mode frequency ?
what is the rule of selecting the CMFB loop frequency ?

Thank you in advance
Back to top
 
 
View Profile   IP Logged
Jacki
Senior Member
****
Offline



Posts: 213

Re: CMFB loop bandwidth requirement for differential amplifier
Reply #1 - Mar 17th, 2019, 1:37am
 
if you want a stable loop, at least your CMFB frequency should be higher than 3dB frequency in the differential mode.
Back to top
 
 
View Profile   IP Logged
Salim2019
New Member
*
Offline



Posts: 5

Re: CMFB loop bandwidth requirement for differential amplifier
Reply #2 - Mar 17th, 2019, 1:53pm
 
Dear friend,
Thank you very much for your reply
My CMFB loop is not stable as I came to know that it has higher GBW than the GBW of the differential amplifier and hence polse from differential introduced to it and degraded the stability.

Thus I am going to decrease the CMFB loop bandwidth to improve the stability
Back to top
 
 
View Profile   IP Logged
Pages: 1
Send Topic Print
Copyright 2002-2019 Designer’s Guide Consulting, Inc. Designer’s Guide® is a registered trademark of Designer’s Guide Consulting, Inc. All rights reserved. Send comments or questions to editor@designers-guide.org. Consider submitting a paper or model.