what is the topology?

[tommydidi]

It will be greatly appreciated if some one can point me to the reference material.


Thanks,
Jim

 

[frankrose]

This is a source degenerated differential pair. The degeneration resistor value depends on the Rds.on of the FETs. Basically used to decrease gain and increase linearity of the diff.pair.
For source degeneration a good manual: Behzad Razavi - Design of analog CMOS integrated circuits, see single ended amplifiers

 

[sutapanaki]

This is a source degenerated pair used in the 1990s to build transconductances for Gm-C filters. You can find it in papers from that time.