PLL configures to program in integer mode by default when fout/fref = rational number. is there a way to DISABLE this function and still program in fractional mode?

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brcuc_2268776
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"Fout/Fref appears to be a rational number, PLL configured for Integer-N mode for best jitter performance (FS0)." highlighted below -

Does anyone know if there is a way to disable this default function & still program the part in FRACTIONAL mode and NOT INTEGER mode?

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PradiptaB_11
Moderator
Moderator
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500 replies posted 250 solutions authored 250 replies posted

Hi Brooke,

The integer mode provides the best performance, so the clock wizard software is programmed to set the Integer mode PLL when PLL frequency differs lessthan 30-ppm between fractional and integer Mode.

There is no  way to disable this fucntion. You may need to change the reference input to achieve a fractional PLL setting.

Thanks,

Pradipta.

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PradiptaB_11
Moderator
Moderator
Moderator
500 replies posted 250 solutions authored 250 replies posted

Hi Brooke,

The integer mode provides the best performance, so the clock wizard software is programmed to set the Integer mode PLL when PLL frequency differs lessthan 30-ppm between fractional and integer Mode.

There is no  way to disable this fucntion. You may need to change the reference input to achieve a fractional PLL setting.

Thanks,

Pradipta.

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