LMK5C33414AEVM: 1PPS on LMK5C33414AEVM

Hi Jennifer,

Thanks for your answer. Unfortunately it doesn't work. You'll find my Tics Pro file and a screenshot of the status as an attachment.

Can you send me a working Tics Pro file please ? For information, I'm using the EVM board without any change and I've got the 1PPS input on IN0_P and the 1PPS output on OUT0_P.

Thanks a lot,

Have a nice day,

Coline

lmk5c33414a_23-01-25_4.tcs

Hi Coline,

We can provide a 1PPS file within the next few days.

Regards,

Jennifer

Hi,

That would be great, thank you !

Have a nice day,

Coline

Riley Nguyen, please upload when possible.

Regards,

Jennifer

Hey Coline,

Please try this config file for 1PPS input and outputs. In this config, I have XO 48 MHz, 1PPS to IN0 (REF0), 1PPS outputs on OUT0-1. OUT9 is enabled with 122.88MHz for testing purpose to ensure APLL3 is lock and produce a correct output frequency. For DPLL to lock, REF0 need to be validated (REF0_VALLID_STATUS = 1), so make sure to have 1PPS input signal is good for the device to validate.

It is possible to use external source for XO signal.

If you're using a SigGen or external XO boards, connect to SMA connector XO_P. The jumper JP4 by default selects DC/DC to power the on-board TCXO, so you need to change the jumper header to GND to disconnect the TCXO signal path.

The EVM also have other footprints for XO. If you need to solder external XO to LMK5C33414A EVM, remove R43 connecting the on-board TCXO and populate the resistor for the footprint being used . Refer to LMK5C33414A EVM User Guide section 3.5 and section 4.8 for XO input signal and schematic.

-RileyLMK5C33414A, 48 MHz XO, 1PPS IN0, 1PPS OUT0-1.tcs

Hi Riley,

Thank you for your answer. Unfortunately it still doesn't work. 

For information : 

- The board is powered by 12V on Vin4.

- I've got a 1Hz / 2.3V signal at the IN0_P input and no detection in the status.

- I've got the 1Hz signal at the OUT0 output (but not synchronized with the input while it doesn't detect it).

I will also better explain my need : 

I've got a 1Hz signal (this is the GPS' synchronization PPS) that arrives in the LMK5C33414AEVM.

I would like to have this same signal coming out of the LMK5C33414AEVM (synchronized in frequency and phase with the input one) when everything is fine and if I stop the input signal (for a long time, many hours), I would like the output signal to continue as if the input signal had never stopped, still synchronized in frequency and phase with the one that stopped.

I also saw on your TICS PRO configuration that you don't use ZDM. Don't we need it ?

Thank you for your help,

Have a nice day,

Coline

Hi Coline, 

ZDM is not required to synchronize the output to the input. Synchronized means the output phase follows/tracks the input phase and the output is phase locked to the input.

ZDM is used if the output to input phase relationship needs to be deterministic, which means that the phase difference stays constant across boot-up or software reset. Is ZDM required for your application?

Riley Nguyen, please support in the debug.

Regards,

Jennifer

Hi Jennifer,

I think that I need ZDM since I want my output synchronized in frequency and phase with my input and without phase shift. The output must be exactly the same signal as the input.

Thank you for your help,

Coline

Hi Coline,

Yes you would need ZDM to have phase deterministic between input and output. If you need phase alignment, once ZDM is established, that could adjust through DPLLx_PH_OFFSET.

When loss of reference is detected, the device enters holdover - where the output still stays in locked until the reference is back valid. During holdover, it locks to the XO and frequency stability of long term holdover depends on XO being used (OCXO > TCXO > XO).

For the config, seems like REF0_VALSTAT = 0?

Make sure to use the latest TICS Pro. Could you readback REF0_ITYPE (R68)?

-Riley