LMX1214: Phase noise performance for AUXCLKOUT

Kei Kuwahara

Part Number: LMX1214

Tool/software:

Hello team,

My customer wantst to use AUXCLKOUT as addtional clock output because they want to generate 2 different frequencies with LMX1214.

Is the phase noise performance of AUXCLKOUT same as the normal CLKOUTx pins?

Best Regards,
Kei Kuwahara

over 1 year ago

0 vicente flores prado over 1 year ago

TI__Mastermind 29402 points

Hi Kei,
Is there a specific frequency customer wants to check?

The noise floor is different from the outputs vs AUXCLK:

Regards,

Vicente

0 Kei Kuwahara over 1 year ago in reply to vicente flores prado

TI__Expert 7860 points

Hello Vicente-san,

Thank you for your quick reply!

Customer is considering to output 400MHz and 800MHz with single LMX1214.
(Input clock frequency is 1600MHz)

I believe AUXCLKOUT is capable of up to 800MHz output.
Which frequency would result better phase noise for AUXCLKOUT, 400MHz or 800MHz?

Best Regards,
Kei Kuwahara

+1 vicente flores prado over 1 year ago in reply to Kei Kuwahara

TI__Mastermind 29402 points

Hi Kei,
That is correct:

So customer plans to use the device in buffer mode with either a 400MHz or 800MHz output?
I would anticipate the 400MHz output having better phase noise performance.

Regards,

Vicente

+1 Noel Fung over 1 year ago in reply to vicente flores prado

TI__Guru** 109470 points

Hi Kuwahara-san,

Here is some test data, input is 1.6GHz.

0 Kei Kuwahara over 1 year ago in reply to Noel Fung

TI__Expert 7860 points

Hello Noel-san,

Thank you very much for the measurement!

This helped me a lot!

Best Regards,
Kei Kuwahara

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LMX1214: Phase noise performance for AUXCLKOUT