Scott
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I am trying to match lab measurement of short circuit noise for my pipeline ADC. In order to accomplish this, I set up a PSS/PNOISE/PAC analysis for the first 3 MDAC stages and the S/H stage of the pipeline. I set PSS to have a beat F=fs/4. This appears to work fairly well, but I have a couple questions.
First, the PAC predicts a 6dB voltage attenuation across the S/H. Is this expected? The S/H does have a return to VCM forced during the sample stage by shorting the S/H positive and negative outputs.
In the simulation I have 3 MDAC stages with a 2X gain per stage, resulting in a 8X gain from the output of the 3rd MDAC to the output of the S/H. Referring the noise at the MDAC output to the S/H input is easy (divide by 8), but when referring to the S/H input (to match the lab data) should I include the 6dB attenuation of the S/H?
Thanks, Scott
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