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LMK04832: JESD204B compliant clock distribution of low frequency with ultra low phase noise

Daniel Stindl
Intellectual 325 points
Part Number: LMK04832

Hello

We have clock source with frequency 122.88-125MHz and with ultra low phase noise on 20Hz to 1kHz offsets (circa 20Hz@<-100dBc/Hz, 100Hz@<-135dBc/Hz, 1kHz<-157dBc/Hz).

We are looking for solution of clock distribution of this source where outputs phase noise on the specified offsets are degraded as low as possible - ideally by 3dB max.

The solution should be JESD204B compliant. The minimum of number of outputs is 14 (4 clk/sysref pairs for ADC, 3 clk/sysref pairs for FPGA (jitter is no care)).

We are gonna measure this clock source with LMK04832EVM in distributed mode but I don't think we will achieve desired performace (according to datasheet).

Can you please recommend a device or combination of devices suitable for this job?

Thanks and regards

Dan

  • 0
    TI__Mastermind 27661 points

    Dan,

    The LMK04832 is our only JESD compliant buffer/divider that we have for now and it does have the right number of outputs.

    We don't have a lot of phase noise in distribution mode data for close-in in distribution mode.  For LVPECL2.0, PLLatinum Sim predicts -160 dBc for 122.88 MHz carrier.  But this is the noise floor, so at these low offsets, you could be impacted by the flicker noise.

    Regards,
    Dean