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Altera_Forum
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16 years ago

PLL 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-...
Altera_Forum's avatar
Altera_Forum
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16 years ago

The VCCIO hasn't been mentioned. For some reason I expected 3.3V, but this is possibly wrong. However, there is effectively no difference in output driver operation between SSTL and other single ended standards. Both are choosing a driver impedance by enabling or disabling output transistors (from three or four available). Depending on the IO standard, it's either named drive strength or series termination.