enigma2020
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Posts: 3
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Hi all,
first of all, thanks for replying to this problem. To answer some of your questions. This is a specter simulation ran with ideal opamps and non-ideal switches. The ADC DAC was modeled in verilog-A and the values were updating correctly in the correct phases.
The solution to the problem above is a setup issue. Basically my sampling frequency was supposed to be 256 kHz so the period of my VPULSE should be 1/256kHz. Which comes out to 3.90625e-6. I put 3.9us as my sampling period so what happens is when I run my simulations and plot the FFT, I do not satisfy the coherent sampling condition. Once I used the correct sampling frequency. The results from the FFT turn out correct. There are not more tones in my PSD plot and I have a 2nd order noise shaping curve.
Thanks again for your responses. ;D
Cheers.
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