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Altera_Forum's avatar
Altera_Forum
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18 years ago

Calculating jitter

I see a PLL output jitter spec of 25mUI for clocks less than 100MHz. Does anyone know how to calculate the output jitter with this spec?

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    25x10ˆ-3 (10ns) = 250ps

    Where 10ns is the period of the clock you are using.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    UI is unit interval, which is the period of your clock in this case. mUI is 0.001UI. Based on that you can calculate your jitter for whatever period clock you have.