AX5043/AX5243 external components recommended value

Hi,

Could you tell me the recommended value of the external coil (Lext) and the external input clock (fext) for receiving 314.98Mhz with AX5243 / AX5043.
Also, if there is an adjustment method using registers, etc., could tell me the adjustment method as well.
I think that the approximate value for those components are set and the some registers is changed to match the desired frequency. Is that really correct?
If it is correct, I would like to know the detailed method.

Could you tell me the recommended value of each components of the ANT input circuit for receiving 314.98Mhz with AX5243 / AX5043. …
(LC1,2 / CC1,2 / CT1,2 / LT1,2 / CM1 / CM2 / LB1,2 / CB2 / CF / LF / CA)
If you have a calculator tool or spread sheet, could you share it with me?

Best Regards,

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Hi,

Do you have an update for this topic?

Best Regards,

Hello! Answering your questions:

  • recommended value of the external coil (Lext)
    • as shown in Table 9 of the AX5043 Datasheet, to cover the 315 MHz you should use an Lext = 18 nH. The actual range may differ on your specific setup with your specific inductor producer so the best is to test on your PCB.
    • the target is to have an Lext such as the PLL ranges on your central frequency with a RNG=8 (in the middle) to allow the PLL some ranging margin below and above your center frequency.
  • external input clock (fext)
    • If you mean TCXO/XTAL frequency, the best is to select a crystal which frequency is not an integer fraction of your operating frequency. Both the 48MHz TCXO (on our ADD5043-433) or 16 MHz (on ADD5043-169 ) will be fine.
  • I think that the approximate value for those components are set and the some registers is changed to match the desired frequency. Is that really correct?
    • the best is to start from a new AX-RadioLab project. You can set all the parameters of your PHY via the GUI and RadioLab will automatically calculate the optimal register settings. You can inspect these registers via the “Edit Registers” panel or review the generated config.c file. Details on each register can be found in the AX5043 Programming Manual.
  • Could you tell me the recommended value of each components of the ANT input circuit for receiving 314.98Mhz with AX5243 / AX5043.

Regards,
Georgi

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