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jAlter's avatar
jAlter
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1 year ago

Schmitt Trigger at MAX10 PLL dedicated input

MAX 10 devices feature selectable Schmitt Trigger on all inputs. The question is if the dedicated PLL input pin is affected by the Schmitt Trigger when it is enabled, or if the PLL input bypasses the...
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FvM's avatar
FvM
Icon for Super Contributor rankSuper Contributor
2 months ago

Hi,
I had an occasion to measure properties of MAX10 clock input and found above expected behaviour. A configured Schmitt Trigger feature also works on PLL input. I could specfically see that a low slew rate clock signal as shown below caused loss of PLL lock with 3.3V LVCMOS IO standard but runs fine with 3.3V Schmitt Trigger input.

Regards
Frank

 

  • jAlter's avatar
    jAlter
    Icon for New Contributor rankNew Contributor
    2 months ago

    Very useful test.

    Thanks Frank,