I am designing in an LMK00334 to distribute a clock.
Does the part have any requirements for power supply sequencing? Does it mater what order I bring up Vcc, Vccoa, Vccob and Vccoc?
I am only using one of the two clock inputs. CLKin1 and OSCin will not be used. Can I leave them floating, or how should I terminate them?
Thanks.
When powering the Vcc and Vcco pins from separate supply rails (e.g. Vcc = 3.3 V, Vccox = 2.5 V), it is recommended for the supplies to reach their regulation point (+/-5%) at approximately the same time while ramping up, and reach ground potential at the same time while ramping down. Using simultaneous or ratiometric power supply sequencing prevents internal current flow from Vcc to Vcco pins that could occur when Vcc is powered before Vcco.
Simultaneous and Ratiometric supply ramp up/down examples are shown in Figures 2 and 3 in this link:
Unused inputs can be left floating.
Regards,
Alan
