I’m finding it difficult to find a clear answer on ngspice noise simulation support. When I try to simulate a simple circuit with a resistor and a voltage source, I get an error about frequency vectors not being found. I haven’t been able to find any posts specifically related to noise simulation with Kicad 8, so I’m hoping for a clear yes or no from someone who knows, and maybe simple test case if someone has gotten it working.
Ngspice does support noise simulation. However, I think this isn’t really fully integrated into kicad yet (although it‘s been a while since I looked at it). So I think what can be done: Use kicad to create the netlist and then manually feed this into standalone ngspice.
I thought I would elaborate a bit more on my question, because I still can’t find any clear official statement on whether or not noise simulation is supported. I would have included a few more screenshots, but I’m only allowed a single image as a “new user”.
I have made a simple test case with a voltage source and a resistor. I setup the simulation as shown in the dialog to and the following netlist was created:
.title KiCad schematic
.save all
.probe alli
.probe p(Vv1)
.probe p(R1)
.noise v(vo,) v1 dec 100 10 10k 1
Vv1 Net-R1-Pad2 0 DC 10
R1 Net-R1-Pad2 vo 100k
.end
The result in the console log shows that a parameter was not passed to ngspice:
It doesn’t matter what value I set for the reference node, it is always cleared in the netlist sent to ngspice. Is this a bug, am I doing something wrong, or is noise simulation not supported at all (not withstanding that there is an explicit option to run it as an analysis type in the spice workbook)?
PS: I have since upgraded to Kicad 9 and get the same result as in 8.
Thanks for any feedback that anyone could offer.