LMK05318B: Multiple LMK05318B output clock phase synchronization

Hello Colin,

Yes, the LMK05318B can achieve multi chip output phase synchronization. 
Using the Zero Delay Mode (ZDM) will give you phase determined outputs as well as link the input and output to get phase determine outputs as well as to link them on the same phase. You will also need to configure all of the outputs to be synchronized on the same APLL. 
Also if IEEE 1588 PTP clock steering is necessary we are able to program the device in DCO mode to achieve this.

Here is an image from the datasheet describing some of the functionality as well as additional sections with information.

Please let me know if you have any other questions and I can further assist in creating a configuration plan.

Best Regards,
Kyle Yamabe

Hello Colin,

I would like to follow up from my previous answer I made an incorrect assumption because your output clock signal is 12.5MHz.
The ZDM feature of the LMK05318B only allows for phase determinism of 1 PPS input AND output. The way the ZDM feature was designed in the LMK05318B ZDM does not work with larger frequencies.

To achieve a multi chip output phase synchronization it is best to use the LMK5B/5C parts. This part can achieve multi output phase synchronization and provide phase determinism between 1 PPS input and different clock output signals. If you have a frequency plan with number of outputs, required frequencies, and phase timing requirements I can assist more in which part to choose as well as how to configure the device to achieve this.

Sorry for any confusion I may have caused.

Best Regards,
Kyle Yamabe

Hi Kyle,

At present, we have LMK05318B board for verification. We would like to know how to configure the synchronization of two LMK05318B low-frequency outputs, but we did not see the ZDM mode in the specification sheet.

Looking forward to your reply, thank you

What are you trying to achieve from "synchronization" of the two boards? Are you trying to get outputs on both boards to be edge aligned?

Or do you have a specific requirement for the timing delay between the input and output signals?

Can the output frequencies of the board be 1 Hz signals or does the output have to be 12.5MHz?

Depending on the situation and requirements the LMK05318B may not be able to meet the requirements.

Best Regards,
Kyle Yamabe

Hi Kyle,

We require multiple output clocks of the same frequency and phase in the local area network application. We want to try whether the clocks output by two boards can be synchronized. Currently, regardless of frequency, can two LMK05318 achieve same frequency and phase output? How should the output edge be configured in TICS Pro? We can give it a try. Thank you

Hello Colin,

What is the timing delay requirement between the outputs from each board?

The LMK05318B cannot achieve true ZDM and synced outputs but there may be a workaround depending on your timing requirements.

By connecting both boards and locking to the same input reference if we use the SYNC outputs and toggle the SYNC_SW at the same time on both boards the outputs may be somewhat close to phase aligned. There may be larger time differences between the boards and also will change based on the configuration of the devices.

For true synchronization of outputs you would need to use the LMK5B/5C part.

Best Regards,
Kyle Yamabe