How to set up noise simulation in Cadence SpectrS

[tia_design]

Hi, you guys,
I'm trying to design low noise Op Amp. But I'm not sure the way of my noise simulation is correct or not. In SpectrS, I open up the "Analysis" dialogue, and select type "noise", then specify the frequency range as 1Hz to 15MHz. The following work is to select input and output noise source. As for the output noise source, I select voltage and then click output node in the schematic. As for the input noise source, I don't know how to select it. in my schematic, I have 1.5V DC voltage source connected to the op amp, so I also choose voltage source and click on this 1.5V DC source, but there is nothing appeared in the box.

By the way, in some other software, noise simulation should be done along with AC analysis, how about that in Cadence SpectrS?

 

[alvays]

Sorry I only know hspice well. But I think they are same to theory.

In hspice, there is two elements you should specify: one is the node where the noise you wanted is summed. and the other is the input ac source to be used as the noise input reference, where you get the equivalent input noise.

So I think you may insert a ac voltage source in serise with your dc voltage source.