LMX2595: spur

Amy Luo

Part Number: LMX2595
Other Parts Discussed in Thread: TPS62150

Hi team,

When our customer uses LMX2595 to generate 10GHz frequency, there is spurious at 1.25MHz from the center frequency. What are the possible causes and what should be analyzed from?

over 3 years ago

0 Noel Fung over 3 years ago

TI__Guru* 81400 points

Hi Amy,

what is the reference clock frequency, fpd, MASH_ORDER and PLL_DEN?

0 Amy Luo over 3 years ago in reply to Noel Fung

TI__Expert 6890 points

Hi Noel,

Thank you for your reply.

The TPS62150 used by the customer supplies power to LMX2595. It is found that the switching frequency of DCDC TPS62150 appears in the output spectrum. Is there any way to filter the switching frequency?

0 Noel Fung over 3 years ago in reply to Amy Luo

TI__Guru* 81400 points

Hi Amy,

I think they should consider to use ferrite beans at all Vcc supply pins. The impedance of the ferrite beans should be high at 1.25MHz. Also need sufficient filtering capacitance, suggest >= 47uF.

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LMX2595: spur