Signal aquistion problem

[elhaouati]

Hi
I am working on a signal processing application using the ALPHA250-4. I synchronize the signal sent by the generator with the 10 MHz reference signal of the board. However, I am facing problems at the level of the signal acquisition. According to my understanding, a periodic signal with a frequency 4 times lower than the ADC sampling frequency will appear to the board as 4 repeating samples. My model calculates the phase based on these 4 samples, and if they vary, the calculated phase also varies. Normally, some variation around a specific value would be tolerated assuming that its due to noise. However, in my case, the calculated phase fluctuates across the entire range of possible values.

Note that my phase calculation model works fine during testing, using a block that generates 4 samples (instead of a signal at 62.5 MHz). This leads me to consider that the issue may be related to the signal acquisition part.

Thank you in advance.