Hi!

During recent pnoise simulations two questions came up.

First, why does the list as produced by the 'noise summary' option (of the 'analog design environment') add up to more than 100%? Doesn't it take the correlation between noise sources into account or so?

Second, due to inclusion of a semi-digital datapath to an existing oscillator the beat frequency has halved; the state of the resulting circuit is now periodic with twice the clock period. During the calculation of the phase noise of the oscillator I started doubting about the sidebands to include in the pnoise analysis to account for noise folding. Am I right to include all sidebands up to the preferred maximum sideband? Or should I only include the even sidebands (so exlude the odd sidebands)?

Thanks a lot in advance!

Paul

If the output format has been selected as V^2/Hz, it definitely sounds suspicious. I think you should report it to customer support - you'll almost certainly need to provide a testcase - so that it can be investigated further.

Regards,

Andrew.