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Altera_Forum
Honored Contributor
Honored ContributorNCO Frequency modualtion
Hi, I am trying to make a frequency sweeper with an NCO. Can anyone tell me how the modulation input into the NCO works. I want it sweep from 1MHZ to 48MHZ? Thank you in advance.
Altera_ForumHonored Contributor
Honored ContributorOr better if you start with a value that produces tuning word for 1MHz then decrement by the step and rollover at tuning word that produces 48MHz.
Note that to produce 48MHz you need 96MHz Fs in order not to violate sampling theorem. In fact Fs should much higher to avoid close images e.g. 150MHz or more. You will also need to consider the update rate not to be too fast
