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LAUNCHXL-CC1352P: 200 ohms load impedance

Carlo
Expert 7715 points
Part Number: LAUNCHXL-CC1352P

Hello E2E,

In this application report, it was stated that at 2440MHz high Power PA target load impedance is 200 Ohm. Where is this 200 Ohm located in the LAUNCXL-CC1352P-2 schematic?

Regards,
Carlo

  • 0
    TI__Mastermind 33190 points

    Hi Carlo,

    We are in the process of updating this document and the latest recommendation and load impedance is the following:

    • 20 dBm Tx PA 2440 MHz
      • Load impedance: 26+j25ohm
      • 2nd harmonic impedance: 4+j15ohm
      • 2nd harmonic attenuation: 45 dB_min
      • 3rd harmonic impedance: 406-j19ohm
      • 3rd harmonic attenuation: 60 dB_min

    Regards,

       Richard

  • 0 in reply to RGW
    TI__Expert 7715 points

    Hello Richard,

    Does it mean that in Tx Mode, if we connect a Network Analyzer after the C58 (47pF) (before the RF Switch) on the of LAUNCXL-CC1352P-2, we should measure a Load in the range of 26+j250 ? Please confirm.

    Regards,
    Carlo

  • 0 in reply to Carlo
    TI__Mastermind 33190 points

    Hi,

    No, the impedance is the desired load impedance seen from the chip.

    The main recommendation is to copy the reference design, then this impedance is optimized.

    Regards,

       Richard

  • 0 in reply to RGW
    TI__Expert 7715 points

    Hello Richard,

    So what is the impedance at the single-ended point  (after the C58 (47pF) (before the RF Switch) with  TI reference design circuit? Is it 50 ohms or 200 ohms?

    Regards,
    Carlo

  • 0 in reply to Carlo
    TI__Mastermind 33190 points

    Hi,

    Just before the switch, the impedance should be close to 50 ohm.

    Regards,

       Richard

  • 0 in reply to RGW
    TI__Expert 7715 points

    Hello Richard,

    Our customer is using a spectrum analyzer connected to the launchpad reference design and they could never reach 20dBm.They only get17dBm and they're using the same component value as per TI matching recommendation.  Will there be an update on these reference design or not and in which document?

    Regards,
    Carlo

  • 0 in reply to Carlo
    TI__Mastermind 33190 points

    Hi,

    Make sure the customer is using the latest version of the SmartRF studio since the power settings have been updated from older versions.

    There are no plans to update this design. 20 dBm is achieved on the LaunchPad. Send the layout in gerber format so we can help review the layout.