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Honored ContributorPLL outputs to drive 50 ohm loads
I need two outputs from a single PLL of CYCLONE-III 3C16. Both the outputs are single-ended. One of outputs is 100MHz and the other is 120MHz-200MHz which will be dynamically configured through NIOS-II with variable phases. Those two outputs should be phase-synchronized. They are going to drive two separate loads of 50 ohm for impedance matching. I wonder if the PLL can provide up-to 30mA for each output in order to drive those two loads of 50 ohm . If not, please recommand practical solutions. Many thanks.
12 Replies
Altera_ForumIf you are driving a single load from each output consider using serial termination as it avoids the constant DC load of the parallel termination at the far side. In Cyclone III (and most other devices) series termination is easy.
- Altera_Forum
The maximum ratings say -25/+40 mA, also internal series termination isn't supported for the 3.3 V node. It mainly depends on the required receive level which isn't nebtioned in your post.
