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ClockBuilder Si5338: Our requirement is 3.3V TTL signal at the output at 200MHz.


I have selected 3.3V CMOS(under Output Driver tab: 3.3V CMOS on A, CLK0 stopped low when output disabled, No inversion) at 180MHz at the outout(CLK0A). RDY and INTR is ON. The output is 200mV(i am not sure why?)



Could you please help to trouble shoot?

  • Discussion Forums
  • A few things to check:


    1. Make sure you click on "Apply Values to Register Map" button after all is configured. Red LED at D3 should remain OFF after configuration is downloaded into EVB. If red LED is on, there is an error and outputs will be off.

    2. Make sure the VDDO0 voltage is present (J26 installed). You can measure at TP5. Should be 3.3V.

    3. Make sure termination components are installed for CLK0A / CLK0B (on back side of board near SMAs, C15 & C17 installed with other components not installed). 

    4. Make sure you're not accidentally grounding the outputs in your test setup.