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Two Calculator Functions -- rmsNoise and spectralPower (Read 3469 times)

ywguo

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Posts: 943
Shanghai, PRC

Two Calculator Functions -- rmsNoise and spectralPower
Oct 05^th, 2009, 8:42pm

Hi Guys,

I try to caluclate SNR of a DAC output in Cadence Calculator. Can you please explain the two Calculator functions?

Quote:

rmsNoise -- Computes the integrated root-mean-square of the total output noise over the bandwidth specified in hertz in the From and To fields.This function is available only in the SKILL mode.

Is this function for AC signal only?

Quote:

spectralPower -- Plots the spectral power for the specified current waveform and voltage waveform. This function is available only in the SKILL mode.

Current waveform is the current waveform for which you which you want to calculate the spectral power.

Voltage waveform is the voltage waveform for which you which you want to calculate the spectral power

Why does this function needs two argument, voltage and current? How does it culculate the spectral power?

Best Regards,
Yawei

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Andrew Beckett

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me about Life...

Posts: 1742
Bracknell, UK

Re: Two Calculator Functions -- rmsNoise and spectralPower
Reply #1 - Jan 3^rd, 2010, 3:33am

Yuwei,

Rather late reply, but for the record...

rmsNoise uses the results from a noise analysis, and computes the root mean square of the noise output.

spectralPower this needs both the current and the voltage (so it can compute the power, it needs both the voltage and current, since this is coming from an AC analysis). It calculates 0.5*real(V*conjugate(I)) .

Regards,

Andrew,

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