Isn't it this the cadence virtuoso version?
I am using spectrum from measurements menu right now but I think there must be something wrong about how I set the DFT:
What I have is the following output (red waveform) from a switched capacitor amplifier for an ADC so at each period of the waveform I am interested in only one time instant.
The 100 MHz clock has an amplification phase and a reset phase (during which output is 0 V) and the idea is to sample the output before the end of amplification phase to send it to the next stage of the ADC.
So I am trying to sample once per clock period (which is twice the waveform frequency which is at 50 MHz) for 2^11=2048 samples.
The first sample is starting at 9 ns rather than 0 so to take samples during the amplification phase.
I get a negative SINAD even when trying with a noiseless transient simulation (noiseless to try understand what is wrong in my DFT), furthermore SNR=SINAD while I would expect huge SNR having no noise in the circuit.
I get the following warnings:
*WARNING* Sample point 1 is interpolated from raw data points.
*WARNING* Sample point 2 is interpolated from raw data points.
*WARNING* Sample point 3 is interpolated from raw data points.
*WARNING* ...
*WARNING* The raw data points are non-uniform.
*WARNING* From/To are not aligned with the raw data points.
*WARNING* 2034/2048 sample points are interpolated, which could cause numerical errors. To remove these errors, use uniform raw data points, and align the sample points with raw data points.
*WARNING* The function values at from and to are not equal.
How can I fix this? How can I use uniform raw data points as suggested?
Also what does it mean by "The function values at from and to are not equal"? Is it that the first and last sample are not equal? (Which I instead suppose they are since the waveform is periodic)
Thanks a lot for help I cannot get out of it