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Help on choosing a clock synthesizer

YH
Prodigy 30 points
Other Parts Discussed in Thread: CDCE62002, CDCE62005

Hello,

I'm looking for a clock synthesizer capable of generating any frequency from a primary and a secondary input clock sources.

Basically, I need to generate 292MHz and 147 MHz from a 10 MHz primary clock reference. If the primary reference disappears, the reference is switched (hitless) to the secondary clock input which would be a high precison TCXO. (like operates Si5326 from silicon Labs in Free Run mode).

Would the cdce62002 be a good choice?Any better option? Is there an any-frequency clock generator from TI which allows automatic switching reference? 

Thanks.

  • 0
    TI__Expert 5725 points

    Hi,

    The CDCE62002 and CDCE62005 is be able to generate 147MHz out of 10MHz. The CDCE62002 has two input one of them is universal REF_IN, but the other one AUX_IN only accepts a XTAL. The CDCE62005 has an additional universal input plus the AUX_IN for the XTAL. Therefore the CDCE62005 would be a better fit. Also the unused outputs (this device has 5 outputs) can be disabled when not used.

    Both devices have a smart mux with holdover so when switching from one input to the other the control voltage of the VCO will be kept so the lock is not be lost. The inputs to smart mux must differ a maximum of 20% between each other for the good functioning of the smart mux (mentioned in page 41 of the datasheet of the CDCE62005, and in the page 29 of the CDCE62002)

    292MHz out of 10MHz would not be achievable with the CDCE62002 or the CDCE62005 out of a 10MHz input. In order to achieve this output frequency the reference should change to another value.