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LMK04805BEVAL: all clkout doesn't work

Part Number: LMK04805BEVAL
Other Parts Discussed in Thread: CODELOADER

i 'm trying to follow the user guide and i got the PLL to lock but it seems there is no output in any of the CLKoutX.

i checked the OSCout and i got output,

Thanks in advance.

  • Hi Yuval,
    Could you change SYNC setting? If all outputs are in SYNC, they will be muted.
    One method is to change "SYNC_POL_INV" bit.
    If the problem is not solved, please send your configuration file.
    If you use GUI Codeloader 4, it can save as a .mac file.
    If you use GUI TICS Pro, it can save as a .tcs file.

    Regards,
    Shawn
  • I changed the  "SYNC_POL_INV" bit and it worked, i can see the signal in output now, but it seems to be offset by a few khz.

    I checked the crystal and the signal generator and they are not the problem, any suggestion? 

  • Please check lock status. In the default CodeLoader modes, LED D5 will illuminate green when PLL lock is detected by the LMK048xxB (output is high) and turn off when lock is lost (output is low). If PLL1/PLl2 is unlocked, the output frequency could have offset with CLKin0 or CLKin1.
    If PLL1 and PLL2 had locked, CLKout frequency ppm offset would follow with CLKin0 or CLKin1.
    If only PLL2 locked, CLKout frequency ppm offset would follow with VCXO.

    Details input, output clocks frequency, or configuration file .mac or .tcs, would help analyze the problem.
  • I changed my CLKin1 configuration to match the default mode and amplified the signal, after pll led illuminated green the output stabilized.
    i saw only dual inputs in the mode menu(counting clkin and vcxo), is it possible to work only with one input of 100mhz instead? i'm working with codeloader4
    thank you for the help

  • Yes, the EVM need be modified in hardware firstly.

    1, Power down VCXO.

    --- Open power supply bead R18.

    2, Select OSCin* SMA connector for 100 MHz reference input

    --- Move C4 0.1uF to R1

    Now for LMK0480x,  VCXO frequency = 100 MHz.

    Then LMK0480x can work in PLL2 only mode.

    Using software "Clock Design Tool" to simulate VCO frequency, Loop filter parameters, dividers.

    Set simulation result into GUI "Codeloader".

    Regards,

    Shawn

  • I made the hardware changes in the board, and simulated the state I want in the "Clock Design Tool" but it doesn't let me save it in a format that the "CodeLoader" software can read. the simulation can be saved in a "sav" format and the clock loader can load "mac" format.
    thank you,
    Yuval.
  • Yes, it is. We have to manual input from simulation to Codeloader. .sav and .mac is used for sharing to other engineers.