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Altera_Forum
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15 years ago

Unwanted frequency shift in DA-converted signal

Hi, i use Matlab/Simulink and DSP Builder for my project. In Matlab, I generate a digital source signal and program it in a LUT-Block in Simulink. This Block then sends the data to my DACs...
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Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Ok, that's it. The not continuous states when jumping to the start of the LUT cause these problems. With a frequency that leads to a continuous signal, as the ones in post# 11 the frequency shift is gone.

The DDS solution also works perfekt.

Now, I'm able to generate signals which are shifted only about 100 Hz. That remaining shift could be because of the crystal is not exactly at 125 MHz. But it's fine for my project.

Thank you again for your help guys. Saved the end of my work day ;)