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CC1175: CC1175 + CC1190

Per Magnusson
Intellectual 480 points
Part Number: CC1175
Other Parts Discussed in Thread: CC1190, , BOOSTXL-CC1120-90, CC1120

Hi,

I'm working on the design of a radio transmitter for 869.525 MHz 500mW. I use CC1175 and intend to connect the CC1190 to have more power. I've got it working with the development system using the CC1175 only . Now I'm adding the radio components to my own circuit board and intend to connect the CC1175 and CC1190 together. When I look at the different reference designs, there seems to be a lot of components used for radio reception. Since the CC1175 is just a transmitter circuit and I need the solution as small as possible, I want to remove everything that is not needed. Can someone help me just to delete the unnecessary components on the design drawings?

I use the reference designs CC1175EM_868_915_schematic.pdf and BOOSTXL-CC1120-90-Sch-A.pdf

Regards,
Per Magnusson

  • 0
    TI__Mastermind 27145 points
    Hi,

    If it is for Tx Only , then you can remove everything in between C174 and P3 (Keep C174 and remove C3) and the circuit (Blaun) on Pins 19 & 20 of CC1175 except C201 (0 Ohms) and L192 (0 ohms) on CC1175EM Schematic .
    Connect C174 output to the input of (Pin-5 - CC112x_RF) ON BOOSTXL-CC1120-90 Schematic Page-2. You need everything on Page-2 of the Schematic except P6.

    You can post your Schematic in PDF, when it is ready. We can review it.

    Thanks,
    PM
  • 0 in reply to PM
    Intellectual 480 points

    Thank you for the answer.
    Can I also remove the SAW filter (FL2) on the  BOOSTXL-CC1120-90 schematic diagram? Any other components that can be removed on the  BOOSTXL-CC1120-90 page 2 schematic?

    Regards,

    Per

  • 0 in reply to Per Magnusson
    TI__Mastermind 27145 points
    Hi,

    We are discussing internally on this topic and I will get back to you soon with proper solution.

    Thanks,
    PM
  • 0 in reply to PM
    TI__Guru**** 317180 points
    When the CC1120+CC1190 reference design was made the SAW filter was required on the highest power levels since the phase noise made the board fail the limit around 863 MHz without. The restricted band edge has been changed in the last EN300 220 to be at a lower frequency meaning that it's possible that the design will pass without SAW filer but I don't have any boards without SAW filter to test with. To be on the safe side you can include a SAW filter but also a 0603 footprint under the SAW filter to bypass it to simplify testing if wanted.
  • 0 in reply to TER
    TI__Mastermind 27145 points

    Hi,

    We discussed internally and we recommend the following.

    CC1175 Schematic:

    • Remove L191, C201, L201, C191, L192 & L193
    • Ground Pin 19 (LNA_P) and Pin 20 (LNA_N) on CC1175
    • Remove the connection from Pin-18 ( TRx)  to C181
    • Ground C181
    • Remove P3 and connect this port to the SAW Filter

    CC1190 Schematic (BOOSTXL-CC1120-90):

    • Put an option (0603 Foot print ) to by-pass, if SAW Filter is not required ( as suggested by TER)
    • Remove C34 and Ground Pin-5 (LNA_IN)
    • Remove the connection from Pin-4 ( TR_SW)  to C36 and Ground C36
    • Replace J3 with 0 Ohm Resistor ( this will be helpful for testing. if you want you can keep the connector)
    • Remove P6
    • Connect R23 to VDD_CC1190
    • Remove R24 and Ground Pin-7 (LNA_EN)
    • Connect R25 to VDD_CC1190

    Please post your Schematic in PDF for our review, when it is ready.

    Thanks,

    PM

  • 0 in reply to PM
    Intellectual 480 points

    Thank you for your help. I will implement this in my schematic and post it for review when I am ready.

    Regards,

    Per

  • 0 in reply to Per Magnusson
    Intellectual 480 points
    Hi PM
    In earlier post you said "Connect C174 output to the input of (Pin-5 - CC112x_RF) ON BOOSTXL-CC1120-90 Schematic". Meaning that I shall remove L172, C176, L173, C175, C177, L174 and P3. Is this still the case considering previous post?
  • 0 in reply to Per Magnusson
    TI__Mastermind 27145 points

    Hi,

    No, those are required. So, please keep them.

    The following is our consolidated final list. Please follow this and ignore all the other previous posts.

    CC1175 Schematic:

    • Remove L191, C201, L201, C191, L192 & L193
    • Ground Pin 19 (LNA_P) and Pin 20 (LNA_N) on CC1175
    • Remove the connection from Pin-18 ( TRx)  to C181
    • Ground C181
    • Remove P3 and connect this port to the SAW Filter

    CC1190 Schematic (BOOSTXL-CC1120-90):

    • Put an option (0603 Foot print ) to by-pass, if SAW Filter is not required ( as suggested by TER)
    • Remove C34 and Ground Pin-5 (LNA_IN)
    • Remove the connection from Pin-4 ( TR_SW)  to C36 and Ground C36
    • Replace J3 with 0 Ohm Resistor ( this will be helpful for testing. if you want you can keep the connector)
    • Remove P6
    • Connect R23 to VDD_CC1190
    • Remove R24 and Ground Pin-7 (LNA_EN)
    • Connect R25 to VDD_CC1190

    Please post your Schematic in PDF for our review, when it is ready.

    Thanks,

    PM

  • 0 in reply to PM
    Intellectual 480 points

    Hi, Here is my schematic diagram, please review.

    Thanks,
    Per

    S4066000.pdf

  • 0 in reply to Per Magnusson
    TI__Mastermind 27145 points

    Hi Per,

    Attached is the Review.

    If you need any clarification, please let me know.

    Thanks,

    PM

  • 0 in reply to PM
    Intellectual 480 points

    Thank you for your help, it is much appreciated.
    Just one comment: LNA_& LNA_N does not exist on CC1175, pin 19 and 20 is GND (0V)

    Regards,

    Per

  • 0 in reply to Per Magnusson
    TI__Mastermind 27145 points
    Hi,

    Yes, I agree with you. But in our CC1175 Reference Design, it shows LNA_P & LNA_N. That's why I made the comment. I think that applies to CC112x device.

    Thanks,
    PM
  • 0 in reply to PM
    Intellectual 480 points

    Hi,

    I have an additional question regarding the BOOSTXL-CC1120--90 schematic diagram. I can see that a dual matching filter from Murata (LFD21868MMF1D386) is used between CC11XX and CC1190. Can this type of filter also be used on the output of CC1190 this to reduce the number of discrete components?

    Regards,
    Per

  • 0 in reply to Per Magnusson
    TI__Guru**** 317180 points
    No,
    since CC1190 require different impedance compared to CC1120.
  • 0 in reply to TER
    Intellectual 480 points
    Ok, thank you.