Biasing circuit for Folded Cascode Opamp - Please help to design

[jdp721]

Hi,

Can you guys please help me with designing the bias circuit for the fully diff folded cascode opamp (attached) i.e., to generate the bias voltages Vb1, Vb2, Vb3.



I tried to search in many books, but none seem to explain properly the biasing schemes that can be used.

Any reference to related papers/tutorials/books/screenshots will be highly beneficial.

Thanks!

 

[Dominik Przyborowski]

The load transistors are biased by current, so You need to design proper cascode current mirror.
The example of popular one

 

[:Dark_Force]

It's worth looking into "Analog Integrated Circuit Design" from Johns/Carusone/Martin, ISBN 9780470770108. Particularly Chapter 6 ("BASIC OPAMP DESIGN AND COMPENSATION") and 7 ("BIASING, REFERENCES, AND REGULATORS")