Hello Experts,
If the external VCXO does not work (i.e. it is broken.), how does LMH1983 work? It will work on holdover or free-run mode? Also LMH1983 will indicate LOR?
Best Regards,
Fujiwara
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Hello Experts,
If the external VCXO does not work (i.e. it is broken.), how does LMH1983 work? It will work on holdover or free-run mode? Also LMH1983 will indicate LOR?
Best Regards,
Fujiwara
Hello Fujiwara-san,
Happy New Year, hope all is going well for you!
The LMH1983 by default is programmed to work in holdover mode but can be reprogrammed to free-run mode. This associates with Register 0x05 bit 2 [LOR Mode].
By default PLL1 is programmed to 27 MHz - same as reference signal - which means PLL could be providing this frequency but not
We can monitor Pin 11 'NO_LOCK' indicates loss of lock status flag for PLLs 1-4 (active high). On the Users Guide we can see that TP23 can be used as well as LED D3 to monitor LOR.