What are the features of different OPAMP topologies?

[sykab]

Can anyone tell me the tradeoffs of the different opamps' topologies?
For instance, between second-stage, folded cascode and tekescopic...

Thanks

 

[leo_o2]

OPAMP topologies

Folded cascode will have lower input voltage range for PMOS input but consume the largest current.
Telescopic output range is very limited. Two-stage will contribute more poles.

 

[drDOC]

OPAMP topologies

folded cascode may not be able to drive a resistive load. So you might need a buffer stage, or a gain stage, which leads to a two stage topology.

If you want more DC gain, generally you want more gain stages.

If you want bandwidth, generally you want less gain stages.