2stage DM folded cascode's 2nd stage??

[xaptar]

so for following specs, I am trying to use folded cascode followed by common source amp.
i did the fully differential mode folded cascode n got around 76dB gain with all other specs in line, my question is how to add CS Amp at out of folded cascode?
1. 2 CS for each output of DM Folded cascode?
2. any voltage level adjusters or just place Vout of cascode into input of CS?
3. how to/where to add C or R or both for compensation.

Specs:
DC open loop voltage gain > 100 dB
Unity gain bandwidth > 100 MHz
Phase margin between 70 and 75 degrees at unity gain
Vout swing > 2.0 Vp-p (single-ended)
Load capacitance = 1 pF
Minimum Von for all saturated FETs = 200 mV
Process technology = 0.35μm CMOS
Supply voltages are VDD = 3.3V and VSS = 0V (ground)

 

[nitishn5]

1. I guess that you wan a fully differential opamp in the end. So you would have to put 2 CS stages for each output of the folded cascode. If you want a single ended output, then have 2CS stages with a common current mirror load.

2. Is your folded cascode NMOS input or PMOS input? What is the output common mode of the 1st stage? From the answers to these you can figure out whether you need a PMOS CS stage or an NMOS CS Stage.
Post your schematic for a better answer.

3. The compensation RC can come across the gate and drain of the CS second stage. You will need separate ones for both the CS stages. There are other ways of compensating but this is the easiest.

Post your schematic.

 

[xaptar]

how to add 2nd stage? i cant figure it out,, kindly tell me, its urgent.
im getting gain of 72dB and 100MHZ + ug FREQ.
SO HOW TO ADD cs AMP to increase gain to 100dB????
see attachment