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Altera_Forum
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14 years ago

Cyclone IV pin connection Guide line make confuse

Hi all, I am using document number PCG-01008- 1.3 (pin connection guide line of Cyclone IV) as main reference for board design. In Clock and PLL Pins section, there is Connection Guidelines: "In C...
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Altera_Forum
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14 years ago

I guess the reason for AC-coupling requirement is that common voltage level from the clock source might be incompatible with REFCLK input. But if you know what you're doing there is nothing wrong in using DC-coupled connection to REFCLK.