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Design of fully diff amp urgent

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Low frequency Open Loop Gain>=100db

2. Unity Gain Bandwidth>=250MHz

3. Input Referred Offset<.01mV

4. Phase Margin>=60

5. Slew Rate=20v/mus

plzz help whether it will be possible to design fully diff amp with above specs r not..

if nt possible will it be possible to meet atleast any 3 of them can be met r nt(including gain) r around which values we can design them plzz help(gain and GBW is must)
 

fully diff amp design help

How much is the load capacitance?
How much should be the power consumption?
What is the process technology? CMOC, BiCMOS...
What is the feature size?

Above questions are very important to answer then ask about the amp specs. Also specs 1, 2, 4 and 5 is easily achievable, but 3 is extraordinarily difficult. You have to use either autozeroing or chopper stabilization. otherwise the offset should be more than ~5mv.

OpAmp
 

Re: fully diff amp design help

What technology are you using?
 

Re: design of fully diff amp help critical

its cmos technology

vdd=3.3v

C>=1pF

power consumption shud be as low as possible..

feature size::the technology is 0.18μm, but using .35μm transistors which
are in the design kit for analog design...

wat input noise can be achieved with the above parameters to improve the offset noise which spec can be reduced r increased???

am new to this filed plzz explain in detail

Added after 4 hours 58 minutes:

any novel idea to improve slew rate
 

Re: design of fully diff amp help critical

i think a folded-cascode amplifier may satisfy the spec.
you need calculate the important transistors' w/l
firstly, some transistor parameters should be known, such as u*Cox, lambda
then, calculate the w/l of the important transistors by the given spec.
lastly, need much time to simulate the circuit and adjust the w/l
for detailed calculation, you can refer to Allen's CMOS Analog Circuit Design
good luck
 

design of fully diff amp help critical

What's the usage of your amp?
Looking from the specs, it's not difficulty to realize.

hanm
 

Re: design of fully diff amp help critical

actually i require maximum values of each of them may be one can be comprimised but i dont know wat r the achievable maximum values plzz suggest them n topology ...just entered to this field sooo dont no much cud u plzzz guide mee its very urgent plzzzz
 

Hi hanm,

Are you sure it is not difficult?
i think input referred offset < 0.01mV is not easy to achieve if you are not doing sth like chopped stabilized opamp
 

refer philip allen book
 

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