Original Question: AMP Noise Analysis by guorock
Hi,
I want to use ADIsimPE to do the noise analysis, after configure some parameters in "Choose Analysis" as below plot and run the simulation, an error is displayed to say "unknown input source 'V3' for noise analysis". I have tried adding a terminal called "VIN" at V3 and changed the "Source Name" in Noise analysis to "VIN", but seems it still can't work well.
Any suggestions?
BR,
David
Verified Answer: RE: AMP Noise Analysis by JGunao
Hi David,
I think using waveform generator as an input will not work on simulating noise analysis, I will verify this. For now, change the input with a universal source and configure it as a sine wave input. Also, under the noise analysis settings change the mode into frequency instead of device. Then try to run the simulation.
As a reference, below is the screenshot of my simulation.
I hope this helps.
Regards,
Jay
Question: RE: AMP Noise Analysis by ScottH
I think we need to look into this a little bit more. It looks to me like a bug with the ADIsimPE waveform generator source properties.
In other simulators, you need to have an AC 1 source for the input (because noise analysis is based on ac analysis), but the ADIsimPE help file says specifically: "Note that it is not necessary to apply an AC specification to any source - including the optional input referred source - as it is with standard SPICE and many (if not all) of its derivatives."
If I build up the same file as you in the SIMetrix Intro version (based on the same simulator as ADISimPE), it works fine in SIMetrix and it also works fine when I port it into ADIsimPE, but it stops working when I delete the Waveform Generator and place it again from the ADIsimPE menu.
As a work-around, Jay's suggestion will work (make sure you change the value of the source to dc 0V so the input isn't saturated).You could also keep the waveform generator and delete the Source Name in the Noise analysis menu, but then you have to choose "Plot Output Noise" because there is no input noise source.
The schematic I generated with the SIMetrix Intro is attached. I will ask someone to look into the bug.
Thanks!
Scott
Question: RE: AMP Noise Analysis by guorock
Hi, Jay and Scott,
I applied your suggestions and both methods can work in my side.
But seems ADA4841-2's noise plot has not displayed the 1/f noise.