LMX2594: About the setting of LMX2594

akihiko yokouchi

Part Number: LMX2594

Could you please give me some advice?

When MASH_ORDER is "4" and fVCO>10000MHz, PFD_DLY_SET"6" is recommended.
When MASH_ORDER is "4", fVCO>10000MHz, and PFD_DLY_SET is "5", will the operation of the PLL IC become unstable?
If it becomes unstable, do you know what kind of unstable operation it will be?

Regards,
Akihiko Yokouchi/

over 2 years ago

0 Noel Fung over 2 years ago

TI__Guru** 108130 points

Hi Yokouchi-san,

Usually we have +/- 1 digit margin. That is, in this example, 6 is the recommended value, but it may work with 7 or 5.

If it does not work, usually either it will completely unable to lock or phase noise becomes very bad.

PFD_DLY is used to optimize spurs and phase noise, if this value is too big or too small, PLL will not be stable. Keep using the recommended value and adjust no more than +/- 1 when necessary.

+1 akihiko yokouchi over 2 years ago in reply to Noel Fung

Intellectual 340 points

Hi Noel,

Thank you for your advice.

Clock & timing

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LMX2594: About the setting of LMX2594