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?

 

[analogic]

for input, chose the port that u want to refer your ouput noise back to, which generally should be ur ac signal source

once u finish the simulation, choose plot or print ur noise summary to get the result. at that time, u will be able to choose include the resistor noise, and other noise sources.. or not.

hope it helps.

btw, do check Cadence manual CDSdoc, no one is more reliable than CDS doc on the simulation steps.

 

[tia_design]

Thanks for replying.

When selecting input noise source, if I chose port, then click 'Select' button, then the schematic window is active, but what I click in the schematic, the input noise source box is empty. I don't know why. So I have to chose 'Voltage' not 'port', and type in the reference number of Voltage source in schematic, such as '/V4'. Then it is noise output seems reasonable.