buddypoor wrote on Oct 14th, 2012, 3:31am:According to my knowledge the most severe error source in gm-C topologies is the finite output impedance of the controlled current sources.
I do agree with that -
Beyond the less than ideal performance of the
transconductor, you can impedance scale the
device so that parasitics are a smaller amount
of the performance criteria
Parasitics remain constant, and frequency defining
elements become a large part of the equation.
Even that fails however if you have to size scale up
your transistors to deal with higher currents required
to do impedance scaling.