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Analog_Designer New Member Offline Posts: 9 Egypt	CMFB Desing Question May 13^th, 2012, 5:57am I'm working on a Capacitive Feedback Telescopic Cascode OTA Design using 0.35 um technology and i can't design a CMFB without deteriorating the output swing as the Dynamic range is one of the major concerns . any suggestions ? ..... Thanks in Advance .....
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Analog_Designer New Member Offline Posts: 9 Egypt	More details Reply #1 - May 14^th, 2012, 1:55am Okay then ! This was my first question in this forum hoping for the people to interact more than this . Any way the topologies i tried till now are three. the attached file may explain it better than me ... . I hope this time i get an answer .... thanks in advance .....
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Lex

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Posts: 201
Eindhoven, Holland

Re: CMFB Desing Question
Reply #2 - May 14^th, 2012, 4:10am

Are you really expecting us to help you with something that resembles a homework assignment? Wink

Some hints:
- if your swing is a problem, check voltage headroom, and determine what is limiting the voltage headroom.
- if your voltage headroom is the problem, apply some topology that is best for it. Make a good mix and match of NMOS and PMOS. =)

Good luck.

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Analog_Designer

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Posts: 9
Egypt

Re: CMFB Desing Question
Reply #3 - May 14^th, 2012, 12:44pm

Lex wrote on May 14^th, 2012, 4:10am:

Are you really expecting us to help you with something that resembles a homework assignment? Wink

Some hints:
- if your swing is a problem, check voltage headroom, and determine what is limiting the voltage headroom.
- if your voltage headroom is the problem, apply some topology that is best for it. Make a good mix and match of NMOS and PMOS. =)

Good luck.

First: Thank you for your reply

Second : I just need help in my way of learning analog design, by the way i have just been graduated from the faculty of engineering, Electronics and Communication Department in 2011 ,means i'm a fresh graduate, and i'm ,now, working as a VLSI Researcher in a research lab ,just started, i have taken this project to learn and to revise the analog info i have taken in the college and to put them in action ,so, i thought of interacting with people in a forum so as to exchange knowledge and experiences . thank you anyway

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wave Senior Member Offline Posts: 117 Silicon Valley	Re: CMFB Desing Question Reply #4 - May 14^th, 2012, 5:43pm Look at a Switched Cap CMFB circuit
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ywguo Community Fellow Offline Posts: 943 Shanghai, PRC	Re: CMFB Desing Question Reply #5 - May 16^th, 2012, 2:37am The output voltages of OTA are out of the normal operating range of your two CMFB circuits. Yawei
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Question: Power vs Area
power consumption 1 (50%) Area increase 1 (50%) Total votes: 2 « Created by: haykp on: May 14^th, 2012, 5:37am »