CM range for a fully differential op amp

[bhargava834]

I have designed a Fully differential op amp with gain boosting topology in 0.18um technology in ELDO environment. It is designed in such a way that its I/P CM voltage is of 0.65V. If the input offset voltage is other than this, the operation of other transistors is changing from saturation..
And the main problem is when the op amp is connected in feed back topology for settling time measurement, it is very difficult to give the I/P CM voltage to operate every transistor in saturation region.
For this what i have to do??

Thanks for the reply in advance...

 

[karim365]

I have designed a Fully differential op amp with gain boosting topology in 0.18um technology in ELDO environment. It is designed in such a way that its I/P CM voltage is of 0.65V. If the input offset voltage is other than this, the operation of other transistors is changing from saturation..
And the main problem is when the op amp is connected in feed back topology for settling time measurement, it is very difficult to give the I/P CM voltage to operate every transistor in saturation region.
For this what i have to do??

Thanks for the reply in advance...