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Original question:

DAC38RF82EVM: :How do I set parameters (about On chip PLL、 PLL2 configuration 、Clock Outputs、clocking,etc)for the DAC MODE...

DAC38RF82EVM: I want to use the "811 mod"of the DACEVM，I don't want to use J4 to connect to an external reference clock. I want to use On-Board VCXO Clock Mode (CMODE4) Like the picture below. I would like to confirm the Settings of these pa

XIaodie Hu
Prodigy 100 points
Part Number: DAC38RF82EVM
Other Parts Discussed in Thread: TSW14J57EVM, LMK04828

Hello, 

1,When I set the data rate to 9G , the following dialog box will still be displayed(HSDC pro) .How do I do it?

2,I want to use the "811 mod"of the DACEVM，I don't want to use J4 to connect to an external reference clock. I want to use  On-Board VCXO Clock Mode (CMODE4) Like the picture below. I would like to confirm the Settings of these parameters(about On chip PLL、 PLL2 configuration 、Clock Outputs、clocking,etc), as shown in the PPT below h8.docpe.com/Download/021809390957/021809390957.html (by Chase W).

  • 0
    TI__Guru* 91947 points

    Xiaodie,

    Attached are two examples. One uses the LMK for the DAC clock source and the other uses the LMK for the DAC PLL reference. Both use the on-board VCXO (122.88MHz) as the main clock source. When trying to use the EVM with both the DAC PLL and LMK PLL, your options are very limited as the TSW14J57 needs a clock that is serdes rate/40 and this cannot always be provide with the VCXO = 122.88MHz. When this is the case, a second clock source is required or the VCXO needs to change.

    Regards,

    Jim

    DAC38RF82_Fs_5898Msps_841_DAC_PLL_LMK_PLL.pptxDAC38RF82EVM_On_board_VCXO_LMK_2949.12M.pptx  

  • 0 in reply to jim s
    Prodigy 100 points

    Jim,

    Can I do this in order to use 811 mode？I don't know how to set the parameters of Clock Outputs.

    Regards,

    Xiaodie

  • 0 in reply to XIaodie Hu
    TI__Guru* 91947 points

    Yes but you will need to provide a 1105.92MHz external clock to J4.

  • 0 in reply to jim s
    Prodigy 100 points

    Jim

    1，,I want to use the "811 mod"of the DACEVM，I don't want to use J4 to connect to an external reference clock. I want to use  On-Board VCXO Clock Mode (CMODE4) Like the picture below. I would like to confirm the Settings of these parameters(about On chip PLL、 PLL2 configuration 、Clock Outputs、clocking,etc). I don't want to use any external clocks .How to operate?

    2，I want to know how to set the parameters of Clock Outputs ？

    Regards,

    Xiaodie

  • 0 in reply to XIaodie Hu
    TI__Guru* 91947 points

    Like I mentioned in the other post, you are limited to what frequencies you can use when using on-board clock mode. The frequency you are requesting is not a workable option. To set the parameters you must first find out what reference clock is needed by the DAC PLL and what frequency is needed for the TSW14J57EVM. After you identify these two, you then need to see if the LMK04828 can create both of these using just the 122.88MHz on-board oscillator. 

    If you do not care about the DAC frequency, you can operate the setup using the two examples I sent you.