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CC1125: CC1125 PA impedance matching

Frank Pavatich
Prodigy 60 points
Part Number: CC1125


We are a new user of the CC1125. Our requirement is to use the 225MHz to 230MHz band. CC1125 Tx only (LNA_P and LNA_N not connected). The PA needs to be matched to 50ohms because it will be connected to an 80W amplifier. For matching purposes, is there any data on the impedance looking in to the PA pin 17  ? 

  • 0
    Mastermind 6640 points

    As far as I know, a reference design has never been designed for this frequency and hence the optimal load impedance on this frequency is not known. You can try to start from https://www.ti.com/lit/pdf/swra398 and scale the components slightly according to the frequency difference. Since you want to use 80 W, do you need an ideal match, or in other words, do you need max output power from the CC1125 in this use case? I would recommend looking into using a SAW filter or similar on the CC1125 output to have control over the harmonics since the amplification is rather large here. 

  • +1 in reply to TheGhostOf
    TI__Mastermind 18895 points

    Hi,

    Please follow TheGhostOf's advice for this question.

    Regards,

    Zack