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Part Number: LMK03001CEVAL
Other Parts Discussed in Thread: LMK03001


The attached file shows the configuration I use to operate the LMK03001 eval board.

I connected the output of CLKOUT1 to a scope and also removed the AC coupled capacitors from the board and make shorts instead.

The problem is that the scope shows that the clock frequency is 190.4M and not 47.6M as I was expecting.

What did I do wrong ?




  • Hello Yuval,

    Did you get the expected output before you modified the board?

    Does the output waveform look reasonable, good output swing, good edges?  Can you share an image?
      * CLKout0 of LMK03001 is an LVDS output.  It is intended to drive a differential 100 ohm load.  If you AC couple, the load could be two 50 ohms to ground.  However if you remove the capacitor, and connect 50 ohms to ground, this is not the proper configuration for the output and this could be your issue.

    Can you confirm that the PLL is locked?  If not, what is the voltage at the CPout pin?