• TI Thinks Resolved

LMX2592: Fnum and Fden value in TICS Pro

Expert 5125 points

Replies: 5

Views: 96

Part Number: LMX2592

HI Expert,

My customer would like to set RFoutA=4928.67MHz.

They try to set each values in TICS Pro as below,

Fnum=13470000
Fden=245760000
Prescalar=2
N Divider=20

However, Fvco(MHz)=4928.67 became red.

Then, They changed the setting as below,

Fnum=449 (=13470000 / 30000)
Fden=8192 (=245760000 / 30000)
Prescalar=2
N Divider=20

Fvco(MHz)=4928.67 became white(OK).

Question1, Could you please let me know the limitation for Fnum and Fden setting? Do they need to divide by a divisible number? (In case of above condition, divide by 30000.)

Question2, If yes, this limitation is for TICS Pro only? or  it is for even If Actual use case(not use TICS Pro)?

Thanks

Muk

  • Hello Yusuke-san,

    I cannot reproduce this issue.

    This is a valid setting:

    Fnum=13470000
    Fden=245760000
    Prescalar=2
    N Divider=20

    It may be a bug on TICSPRO-SW. Please ask the customer to update to latest version available online and try again.

    Thanks,

    Vibhu

  • In reply to Vibhu Vanjari:

    Vibhu-san

    Thanks for your support.

    Customer is using TICSPRO v1.7.0.0 .

    I think, It is latest version. 

    Thanks

    Muk

  • In reply to Yusuke Mukuno:

    Hello Muk,

    Does the issue still exist after restarting the software?

    Thanks,

    Vibhu

  • In reply to Vibhu Vanjari:

    Hi Vibhu-san,

    They try below, but, this issue is not solved.

    - Restart software

    - Uninstall TICSPRO and install it again.

    They are checking with several conditions.

    1. They found no issue with following conditions, sometimes. (however almost NG)

    Fnum=13470000
    Fden=245760000
    Prescalar=2
    N Divider=20 

    2. In case of the above setting was NG, they try to save this setting data, then they load the setting data. It may work without problems.

    3. In case of customer set below, Almost no issue. 

    Fnum=449 (=13470000 / 30000)
    Fden=8192 (=245760000 / 30000)
    Prescalar=2
    N Divider=20

    Then, when they push "Simplify Fractions" button, sometimes not work.

    Do you have any idea for the root cause of this issue?

    Thanks

    Muk

  • In reply to Yusuke Mukuno:

    Hello Muk-san,

    I found a bug in the TICS Pro code that only appears in cases where PLL_NUM and PLL_DEN are both divisible by a factor of 3. The code with the bug executes immediately before the code which controls the background color of the VCO box. This is not a device configuration error, this is a TICS Pro bug. I have added this to the list of fixes for a future release.

    It makes sense that loading the data does not cause issues, since loading data does not trigger the code with the bug.

    I'm not sure I understand case 3, since 449/8192 is already the simplified fraction and the "Simplify Fraction" button shouldn't cause any update. Were there other actions taken? 

    I have tried attaching an updated version of the file to this E2E post. It may be possible for you to directly patch the bug by closing TICS Pro, copying and replacing the new file into your TICS Pro configurations folder, and reopening TICS Pro. The default place for the LMX2592 configuration files is "C:\ProgramData\Texas Instruments\TICS Pro\Configurations\Devices\PLL + VCO\LMX2592".

    LMX2592_PLL.py

    Regards,

    Derek Payne

    Texas Instruments