difference between SNR and SNDR

[vishnukanchi]

Hi,

Can you let me know what is the difference between SNR (Signal to Noise Ratio) and SNDR (Signal to Noise Distortion Ratio). How do you measure these for an op-amp?.

Regards,
Vishnu

 

[rfsystem]

If the testbench uses a single sinewave source the FFT of the output fives you the wanted and all the rest. If you simulate with spice you will get only the distortion. The noise component could be calculated by the spice AC noise analysis. The output noise should be integrated over the interessting frequency band. This gives the "N".