Channel length reduce in opamp

[ljy4468]

hi!!!

Thanks for answering my question. thanks

I have another problem.
I designed fully differential folded cascode circuit
and reduce channel length(1um->0.5um) (also reduced width, so W/L is same)
and simulated it.
The result is Av is down, unity gain BW is up, PM is up
I know why Av is down.
but why GB and PM is up?
please teach me why

Have a good day
....

 

[winsonpku]

the av is down,for the output resistance is smaller
GB and PM is up,is for size of the transitor is smaller,then parasitic capacitance is small,so the GB is up for the output node parasitc capacitance is smaller,so RC constant becomes smaller,then GB biger.
PM is up,for the second pole becomes bigger for that node's parasitic capcitance is smaller.

hi!!!

Thanks for answering my question. thanks

I have another problem.
I designed fully differential folded cascode circuit
and reduce channel length(1um->0.5um) (also reduced width, so W/L is same)
and simulated it.
The result is Av is down, unity gain BW is up, PM is up
I know why Av is down.
but why GB and PM is up?
please teach me why

Have a good day
....