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Honored Contributor
Honored ContributorCyclone IV PLL min input frequency
Hi, What is minimum input clock for Cyclone IV E PLL? Data sheet states that minimum Fin=5MHz, but PLL locks even to 500KHz input clock freqency. Can someone explain this to me? Thanks
Altera_ForumHonored Contributor
Honored ContributorAs you've found, the spec states fIN(min)=5MHz. Don't rely on all devices operating correctly if you're operating them out of spec.
The only suggestion I have is that the PLL is locking to some harmonic content of your clock source. Cheers, Alex
