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CC1310, 868MHz, Balun

Michael Senghaas
Prodigy 60 points
Other Parts Discussed in Thread: CC1310, CC1101

Is there a balun that can be used with the CC1310 at 868MHz?

  • 0 in reply to Zdenek Vasicek
    TI__Guru**** 317180 points
    0.180 mm vs 0.175 mm will not give any difference in performance.

    If the distance between L1 and L2 is less than 0.175 mm the parasitic caps will increase and they can start to influence the performance since the parasitics will be a larger part of the total cap in a node. On the other hand if the distance between L1 and L2 is too large the inductance in the vias will impact the matching/ ground connections. But the distance between L1 and L2 has to change with more than a few um to impact the performance.

    From the readme: DE104iML or equivalent substrate (Resin contents around 45%, which gives Er=4.42@2.4GHz, TanD=0.016) If the 7628 prepeg has similar spec this can be used.
  • 0 in reply to TER
    TI__Mastermind 33100 points
    The CC1310 IPC (868/915/920 MHz) component from Murata (LFB18868MBG9E212) has now been approved for RTM. This is the same size and pin compatible as the Johanson CC1310 IPC (0850BM14E0016).

    //Richard
  • 0 in reply to RGW
    TI__Mastermind 33100 points
    Samples of the CC1310 IPC (868/915/920 MHz) component from Murata (LFB18868MBG9E212) are now available.

    Please contact Preben at Murata for samples: plarsen@murata.com
  • 0 in reply to Steven3w
    Prodigy 130 points

    Is there an IPC for the CC1310 that works at 433Mhz?

  • 0 in reply to Cameron Jones
    TI__Mastermind 33100 points

    Hi,

    We have had this discussion with both Johanson and Murata for a CC1310 IPC at 433 MHz. Previously, 433 MHz IPCs have not been too popular so this is more business based decision from Johanson or Murata if the IPC will be developed. 

    Regards,

       Richard

     

  • 0 in reply to RGW
    Prodigy 220 points
    Hi, Richard,

    By studying the document for the comparing IPC and discrete Balun filter such as CC12xx, on RX and TX performance, discrete Balun filter show better and IPC shows worse especailly for murata IPC. So two questions: (1) on CC1310, also discrete Balun filter can keep better compareing to IPC? (2) Discrete Balun filter in reference design CAN keep consistence on RF performance by temperature, component tolerance and so on? If yes and we do not consider compact because our design is finished last year, we just keep the discret Balun filter network as your reference design at present.

    BR,
    Roy
  • 0 in reply to chen royce
    Prodigy 220 points
    Hi, Richard,

    Ask your another question: on CC1310 4-layer reference design, the RF inductor use murate ML serial, do you share the data on the TX harmonic on FCC? Is it have good margin on FCC? If replaced by WW inductor, the inductor and cap value is the same as ML ones in balum and filter network? Thanks!

    BR,
    Yong
  • 0 in reply to chen royce
    TI__Guru**** 317180 points
    - The IPC has slightly poorer performance than a discrete balun. Hence a discrete balun should be used if space is not a concern and best possible link budget is the most important.
    - This reference design: www.ti.com/.../swrc309 uses LQW inductors. The radiated margins will be dependent on the type of antenna, for a effective wipe antenna the margin for the radiated 3. harmonic will be low with a 2 - layer design using LQW on max output power.
  • 0 in reply to TER
    Prodigy 220 points
    Hi,

    Thanks very much for your answer. But SWRC309 is for 2-layer. In 2-layer reference design, the inductor/caps value is different from the ones in 4-layer reference design, this difference is caused by PCB stack(4-layer has the better reference ground and the via parasitic inductor than 2-layer) or the different serial inductor(WW inductor has better RF parameter than ML inductor)??? Our understanding is: 2-layer is worse PCB stack than 4-layer in RF application like the different reference ground and the bigger parasitic inductor on via, so 2-layer uses the better WW inductor compensate these to get the good RF performance. Since our finished design is based on 4-layer reference design, we should NOT use the inductor/caps value in 2-layer reference design of SWRC309, right? So we just confirm: ML inductor in 4-layer reference design can have good margin for FCC harmonic??? If yes we just keep these and can you share the harmonic data based on it. If not, can we replace ML to WW to get the better margin by keeping the same inductor/caps value in 4-layer reference design. For example in 4-layer reference design L13,L14 is 6.8nH ML inductor: LQG15HS6N8J02D, we just update them 6.8nH WW inductor: LQW15AN6N8G00D, 6.8nH value is the same.

    Another confirm: Need metal shielding case on CC1310 when comply with FCC part15? If there is emission leakage from bonding or package, it must be neccessary!

    Thanks!

    BR,
    Roy
  • 0 in reply to chen royce
    TI__Guru**** 317180 points
    It could be that I was unclear: Using LQW will give less margin to radiated 3. harmonic compared to LQG. So basically follow the 4 layer reference design, shielding is not required.
  • 0 in reply to TER
    Prodigy 220 points
    Hi,

    Thanks!
    So LQW(WW serial) has less margin(less?) on harmonic than LQG(ML serial) on CC1310? From the others document(swra168a-CC11xx 868915 MHz RF Matching) just for CC11xx chip, on RF performance such as harmonic WW is better than ML inductor because WW has higher Q factor, less tolerance and so on. Can you share the harnomic data based on 4-layer CC1310 reference design? Thanks!

    BR,
    Roy
  • 0 in reply to chen royce
    TI__Guru**** 317180 points
    WW inductors has better Q and lower loss than ML so you will get slightly better conducted performance using WW. But for this reference design WW seems to contribute to the total radiated 3. harmonic. The conducted harmonics are stated in the datasheet.
  • 0 in reply to TER
    Prodigy 220 points
    Understand! Thanks!

    BR,
    Roy
  • 0 in reply to TER
    Intellectual 900 points

    I am curious why there is an extra capacitor (C15 or C16) in swra524a compared to the CC112x IPC reference design. Was this added because the IPC did not perform as expected? Is this capacitor needed for both Murata and Johanson parts?

    EDIT: this is explained on page 4, there is no built-in DC blocking in the IPC. Can you confirm that the CC112x IPC does have DC blocking, and no extra capacitor is needed in that case?


    Also, there is a typo in swra524a on page 5. It says "overall footprint area for all the required components is less than 0.94 mm2", which should be cm2.

  • 0 in reply to Andrew G
    TI__Mastermind 33100 points

    Hi Andrew,

    For the CC13xx IPC, the DC block capacitors could not fit into the ceramic package. If the DC block would of been included, then we would be forced to use a larger ceramic package size for the design. A larger ceramic size would of increased the cost so the DC blocking capacitor was chosen to be external.

    The CC112x discrete ref design inherently contains the DC blocking caps and the IPC is the equivalent circuit. In the CC112x IPC ref design a 100 pF capacitor is used as a switch in the position of C202. I'm double checking that there is no need for a DC blocking cap and will reply with confirmation very soon.

    0.94 mm2 is a typo. 

    //Richard