Corner Simulation for an Amplifier

[gilbertomaldito]

Hi,

I am designing a high bandwidth and high gain multi-stage differential amplifier.
However, at corner simulation, there are transistors that turned to linear and cut-off, but it still meets the specs for AC and DC.
My question is, is it ok to just allow it to happen?

--andrew

 

[Raviprasad_K]

did you check PSRR?

 

[jianjing526]

Hi,

I am designing a high bandwidth and high gain multi-stage differential amplifier.
However, at corner simulation, there are transistors that turned to linear and cut-off, but it still meets the specs for AC and DC.
My question is, is it ok to just allow it to happen?

--andrew

Since the simulation results fullfil all your performance requirements. The design is ok, but you can try to optimize the design. All transistors in saturation is sufficient but not necessary.

 

[rajesh_a03]

I have had similar amplifiers taped-out and it works after we get back. But generally it is because we overlook it during simulations. It is better to fix it.

I generally don't trust the transistor models for cut-off and linear region of operation. If you cannot fix it, make a call on what happens if you add some variation due to mismatch etc. If it doesn't affect performance too much, then it should be ok.