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Altera_Forum
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16 years ago

Cyclone III, huge cap at VCCD_PLL

Hi All! Altera document "Cyclone® III Device Family Pin Connection Guidelines PCG-01003-1.0" says that 470 uF capacitor must be used at digital power of PLL (besides a lot of ceramic capacitor...
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Altera_Forum
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16 years ago

As AN583 reveals, the suggestion is only based on simulations results. I have serious doubts, if the assumptions meet a typical FPGA supply situation. Some lack of practical design experience can be suspected for the guy, who performed the simulation. But I'll check the resonance point with some real world circuits.