This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CDCVF2505: can this device create a fixed propagation delay of 2nS?

Part Number: CDCVF2505
Other Parts Discussed in Thread: LMK04208, LMK04906, LMK03200, LMK01010, LMK01020, LMK01000

Hi Team,

Customer is looking for a solution creating propagation delay 2nS, the reason is if the reference clock to CPU and PCI IC (33MHz) have little time difference, their system works correctly. PCI IC CLK needs about 2nS slower than CPU CLK.

My question is, can we use one CDCVF2505 to achieve this? Or needs a different device to achieve?

Thanks!

Andrew

  • Hello Andrew,

    It appears the CDCVF2505 is designed to operate with +/- 150 ps (typical 0) input to output delay. So true 0-delay. Therefore it's not going to get you the 2 ns propagation delay you would like.

    Consider the LMK03200, LMK04906, or LMK04208 for a device supporting 0-delay with the ability to adjust the actual input to output skew.

    Another option could be to use a buffer/divider like LMK01000/LMK01010/LMK01020. These devices can be placed into /1 mode with some analog delay to get you your ~2 ns propagation delay. The application note SNAA060, Phase Synchronization with Multiple Devices and Frequencies, suggests that propagation delay through LMK01000 is ~600 ps, then analog delay can be turned on with steps of ~142 ps.

    73,
    Timothy
  • Hi Tim,

    Thanks for the crystal clear feedback!!

    Have a good weekend.

    Andrew