SNAS605AS March 2013 – May 2020 LMK04821 , LMK04826 , LMK04828
PRODUCTION DATA.
This mode allows for continuous output of the SYSREF clock.
Continuous operation of SYSREF is not recommended, due to crosstalk from the SYSREF clock to device clock. JESD204B is designed to operate with a single burst of pulses to initialize the system at startup, after which it is theoretically not required to send another SYSREF, because the system continues to operate with deterministic phases.
If continuous operation of SYSREF is required, consider using a SYSREF output from a non-adjacent output or SYSREF from the OSCout pin, to minimize crosstalk.