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Original question:

LMK03806: LMK03806BISQE/NOPB - Design specification -

LMK04808: LMK04808BISQ/NOPB - Clock input query

vinay kumar
Prodigy 110 points
Part Number: LMK04808


Hi Team,

We are designing the following clock generator for our new project. Kindly confirm whether this IC supports 12 outputs and 2 OSC_OUT signals using a single input oscillator clock. Also, please confirm if the IC can accept only one clock input or both an external clock input and an oscillator input at the same time.

Suggest the possible modes of operation for single oscillator input clock and share the programming/adjusting details for the same. 

Also confirm whether the unused clock output can be left floating?

Below attached Block diagram of our design

image.png

Regards,
Vinay

  • 0
    TI__Genius 9890 points

    Hi Vinay,

    This IC can support 12 output clocks and 2 OSC_OUT signals using a single input clock. 

    It can accept an input through CLK_IN which will be jitter cleaned by the first loop. A filter will need to be designed based on the frequencies of your first PLL, and the output of that filter will be channeled into the input pin of your VCXO. That VCXO will input through OSCin, which will then drive the second PLL. So yes, it can accept both of these signals simultaneously. 

    The programming sequence can be developed using TICS Pro GUI, available for download on ti.com.

    Finally, you can and should leave any unused inputs floating.

    Thanks,

    Michael

  • 0 in reply to Michael Srinivasan
    Prodigy 110 points

    Hi Michael,

    We have a single clock input source from an Oven-Controlled Crystal Oscillator (OCXO) connected to the OSCIN pin. Please confirm if this configuration is sufficient to generate 12 output clocks along with 2 OSC_OUT signals.

    Also, kindly confirm the maximum input current and power requirements for this clock generator IC.

    Regards,
    Vinay 

  • 0 in reply to vinay kumar
    TI__Genius 9890 points

    Hi Vinay,

    Sorry for the delay. Your OCXO connected to OSCin will be sufficient. 

    The maximum input current for a clock input is 5mA.

    Thanks,

    Michael