Hi,
Here i am using the LMX2595 in Category 3 and Ref Osc frequency is with in the limits. I gave SYNC s/g (1MHz)from the external pulse generator but could not see deterministic phase . Can any one clarify my below questions
1. In data sheet , it is mentioned that it is time critical. How can i achieve that ? (Would like to check in Lab)
2. In The phase synchronization reference design , what is the procedure to setup Timing critical example?
Thanks
Hi,
To achieve the deterministic phase between the LMXs when it operates in Cat-3, external sync input is needed and it is time critical. That means, SYNC input should meet the setup and hold time for deterministic phase. SYNC rising edge should be min. 2.5ns before the rising edge of the OSCin and should be high till 2ns to meet the SYNC timing requirements.
Regarding the above mentioned reference design, section 4.2.1 shows the example for non-timing critical SYNC input (Cat-2 SYNC), that doesn't necessary to meet setup and hold time. Whereas section 4.3 shows the example for timing critical SYNC, where SYNC input should be in reference to OSCin input with meeting the setup and hold time requirements.
Thanks!
Regards,
Ajeet Pal
