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CC1310: RF Impedance

Teun Noordkamp
Prodigy 50 points
Part Number: CC1310

Tool/software:

Hello there,

Currently I am checking out the CC1310 wireless microcontroller. The plan is to use this chip as a UART wireless interface, and I want to use the differential output with external bias. I know I could copy the reference design but I would like to check the values for the different frequentiebands. So what is the single ended impedance and the differential impedance of this chip (read chip serie) for every band. I know it is not a straight answer because it depends on so many things but I would like to check the reference design before creating my own pcb with possible wrong value's.

Kind regards,

Teun 

  • +1
    TI__Mastermind 18015 points

    Hi Tuen,

    From the CC1310 datasheet (emphasis added for clarity):

    On the Texas Instruments CC1310EM-7XD-7793 reference design, the optimal differential impedance seen from the RF pins into the balun and filter and antenna is 44 + j15.

    However, there is no real advantage to not following the reference designs, and if you have the capability to check your own design(s) then you can of course also look at the released TI reference designs in the same manner. 

    Do you have an EDA tool that can simulate the PCB parasitics and include vendor SMD models? The best method would be to simulate the RF section of the given TI reference design PCB (accounting for vendor SMD models) and then repeat the process for your design(s), aiming to meet the same impedance matching and filter requirements.

    Regards,

    Zack

  • 0 in reply to ZC
    Prodigy 50 points

    Hi Zack,

    Thanks for your quick response. According to your answer and the calculations based on only the real part (44ohm) of the impedance, the component values are within the tolerance range. It is just more the idea of checking the values instead of just assuming that the value's are correct for our application. I have kindof the following filosophie: "Assumptions are the mother of all f***ups". So it is just to double check.

    Kind regards,

    Teun