A Question About Delta Sigma Modulators

[naalald]

I'm designing a 2nd order delta sigma ADC. I want to compare the systematic results with circuit design. In Matlab I have a 73 dB SNDR but in HSpice (all blocks are ideal) I have 66 dB SNDR. I don't know why? What could be the reason?

 

[del-sig]

Hi

I got sigma delta modulator design (.mdl files) from my previous year student. I wanna simulate and have to calculate SNDR/SNR using matlab. I'm using hanning window to get fft. I was wondering how to calculate snr/sndr/dr from matlab.

Thanks in advance

 

[gen0357]

There is maxim application note which describe the matlab routine for the spectral analysis. Check the attachment.

Otherwise there is a routine for SNR calculation in DEL-SIG toolbox. If anybody know the algorithm of this DELSIG routine, please share.

 

[gen0357]

Hi naalald,

The question is too abstract to answer
If possible, share more details about your system (Schematic of both MATLAB & SPICE etc).

 

[bhuvy]

Hi

I got sigma delta modulator design (.mdl files) from my previous year student. I wanna simulate and have to calculate SNDR/SNR using matlab. I'm using hanning window to get fft. I was wondering how to calculate snr/sndr/dr from matlab.

Thanks in advance

hi, can u please share the .mdl files of SD Modulator ???

 

[dawson]

i'm also doing a simulation of sdm.. with simulink block.. but not sure how to calcuate the SQNR. i know need to use FFT block and maybe matlab code to derive the specturm waveform.currently mine is just the simulation waveform.