Hi Paul,
Thank very much for your answer. I tried changing the R and N dividers without any success. As I said before, I don´t think the main problem is loop related since I use the same configuration that works fine when I use the Eval Board. Furthermore, in think that if this was the problem, I would at least see an unlocked output (in contrast to the 0V LVDS signal or +3.3V CMOS outputs I now get).
In my opinion, there seems to be a problem with the VCO. ¿Is there a simple way to check if the VCO is working? ¿Can I apply a DC voltage directly to the LF pin?
Best regards.