sheldon wrote on May 26th, 2006, 10:03am:RG,
There are two issues: measuring the SNR and simulating it. The
only noise in a typical transient simulation is numerical noise and
quantitazation noise. You will need to run transient noise analysis
to simulate the ADC with noise. Calculating the SNR is a pain because
the distortion tones get aliased back into the band of interest. Do
you need SNR or SINAD? SINAD is easier to calculate then SNR.
That is, even I can write a calculator function for SINAD, you will
need Andrew's help for SNR. Let me know if you need SINAD.
Best Regards,
Sheldon
Hi~~~Sheldon:
i have a question about you said calculate SNR "the distortion tones get aliased back into the band of interest"
then i use this : SNR = 10*log [ (signal power ) / ( total interesting band noise power - harmonic noise power) ] to calculate SNR , is it correct ?
or has some other things?
Another question is how should we simulate device noise together with numerical noise ?
is follow the "Device noise simulation of delta-sigma modulators " written by Manolis Terrovitis and Ken Kundert ?
or has other method?
And can we simulate sigma delta modulator totally in cadence spectre enviroment SNR SNDR DR.........?
or has something we must do in matlab?
thanks a lot ~~~~~~