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How to get high UGB(600 MHz) for a two-stage fully differential telescopic OPAMP ?

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Hey guys! Desperately need help regarding a design assignment.

I should use a fully differential, two-stage [telescopic + gain stage] opamp of 0.35um technology and Vdd 3.3V.

The specifications to be met are UGB>600 Mhz, P.M = 60deg and Settling time < 20 ns.

I have read several research papers, but most of them deal with increasing gain or swing for a small UGB. BUT gain is not a concern for me and I can't find any paper dealing with high UGB.

Some sources suggest using a nullifying resistor compensation method. Does it work for this topology and is it worthwhile reading about it ?

Do you guys have any other suggestions in meeting the high UGB specification ?
 

It depends to your power consumption and loading capacitance constraints. With high enough current (2mA) and resonable Cload (10pF), the simple design should met your specification.
 
Thanks for replying. The power consumption should be <3mW and the capacitances >500fF. After some consideration, I've decided to go ahead with the nullifying resistor compensation.
 

For better PSRR and GBW You should use cascode compensation (look for the classic Ahuja, Copeland and Ribbner and Fischer IEEE SSC papers from 1983-1985) especially that your first stage is a telescopic cascode. For load capacitance in order of 1 pF You are able to choose small current ratio between 2nd and first stage, i.e. 2-3 to obtain stable opamp. In this thread You can found some usefull informations also.
 

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