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CC1125: PA Port Matching Circuit for the band 136-174MHz and 403-527MHz

Akshay TM
Prodigy 20 points
Part Number: CC1125
Other Parts Discussed in Thread: CC1311R3

Tool/software:

We found matching circuits for the PA Port of CC1125, but it did not cover our entire bands. Kindly provide us with application circuits that will cover our entire bands or provide us with the impedance values at the PA Port across the mentioned frequencies so that we can design our Matching circuits.

The desired frequency range is:

1. VHF 136-174MHz

2. UHF 403-527MHz

  • 0
    TI__Expert 4860 points

    Hi Akshay,

    I suggest you follow the reference designs available for 169 MHz and 433 MHz:

    https://www.ti.com/tool/CC1120EM-169-RD

    https://www.ti.com/tool/CC1120EMK-420-470

    We have deliberately removed this impedance data from SWRA640 since several customers were deviating from the standard ref design and making a new match purely based on their simulations.

    When simulating a new load match to a source impedance this is just matching the fundamental impedance. With our class DE PA, it is important to keep the 2nd and 3rd harmonics impedance under control as well.

    In addition to the Tx match, the Rx must also be matched for optimum link budget performance. This is not done by just matching the Tx side. In the lab we derive the ref design by performing load and source pull measurements on the chip. It is not recommended just to re-simulate the design and to find a new match.

  • 0 in reply to Diego P
    Prodigy 20 points

    Could we request TI to re-simulate and provide us with matching circuits for our specific frequency ranges, considering this module will be mass-produced? If TI cannot accommodate this request, we may need to reconsider using the CC1125.

  • 0 in reply to Akshay TM
    TI__Genius 17945 points

    Hi Akshay,

    As stated in the CC1125 Datasheet, the CC1125 does not support parts of the frequency ranges listed in your original post:

    For the supported frequency bands, it is not needed to resimulate and design new matching networks; the performance will be very similar across the bands you listed using the reference designs listed in Diego's reply and it is strongly recommended to use those.

    The CC131x wireless MCU family supports a different range of frequency bands, so you can evaluate which more closely fits your requirements. From the CC1311R3 Datasheet: https://www.ti.com/lit/swrs256

     

    Regards,

    Zack