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CC8520 & CC2590

Other Parts Discussed in Thread: CC8520, CC2590, CC8531, CC8530

Hi,

We have implemented the CC8520 and CC2590 reference design and manufactured our own prototypes. Currently we have established pairing and are obtaining audio. The issue we currently experiencing is that the range is only 10 feet than muting of audio is obtained.

My best guess is that the matching network at the output antenna pin of the CC2590 is not matched to 50 ohm. I used the same values cited in the reference design, verified during manufacturing that the 50ohm RF feed trace was impedance controlled.

The only difference is that the inductors used on the reference design in the antenna section could not be obtained and I used a different manufacturer but kepted the same value.

My question is:

When designing the eval board, were S11 parameters and VSWR simulated with specific manufacturer components in mind?

Yohan

  • Yohan,

    Yes, we used components which are listed in the BOM of the ref design and we can not guarantee that it works with components from other vendors. However, the components usually not differ that much between vendors, if you choose the "correct" component from another vendor. If you only get 10 feet range, my guess is, there is something else that is wrong...

    Post your schematic, layout and BOM and I will have a look at it?

    Cheers,

    Per H

  • Per H,

    a) Prefer to get the input impedance of LNA & output impedance of PA for match network investigation for antenna match / bandwidth increase

    b) If available, send us to the s_11 parameters in touchstone format @ 14 dBm output power of PA & 6 dB Gain of LNA; please specify the values of DC supply

    Peter

  • Hi,

    I wanted to thank all the engineers which have helped me and my co-workers in realizing a successfull implementation of the CC8520 + CC2590. 

    I was able to resolve my issue. Essentially I had forgotten to put Vcc on the AVDD_PA2 pin of the chip. Pretty embarrassing, but after that it all came together. The LSO range is more that 125ft. Quality of sound is clear. 

    Again thanks to all of you, this forum is truly the best. Thanks to all!

    Happy Holidays!

    Yohan

  • Perfect Yohan!

    I glad you got an succsessful design, Congratz!

    Just one thing, you should get a bit more than 125ft LOS ;-)

    Happy Holidays!

    Per

  • Hi,

    I was wondering about USB 3.0 and its effect when the CC8531 USB FW 1.2 is released. Will there be any complication? I understand that the market is moving towards the implementation of USB 3.0 and any future products designed with the CC8531 will have to be compatible with this protocol when using the CC8531 as a sound card. Any thoughts?

    Yohan

  • Hi Yohan,

    USB 3.0 should be fully compatible with USB 2.0, so there will not be any complication here.

    -Kristoffer

  • Hi,

     

    Where could I obtain additional information in regards to the PCB antenna used on the CC8520 eval kit. I am currently layout a board with the same antenna design as the eval kit and I am not sure why it is connected to ground and the feed line joins to the pcb antenna.

     

    Thanks for all the advices!

     

    Yohan

  • Hi Yohan,

    Have a look here: http://focus.ti.com/lit/an/swru120b/swru120b.pdf.

    And here: http://focus.ti.com/lit/an/swra161b/swra161b.pdf on page 28.

    -Kristoffer

  • Hi,

    Thanks for the info!

    Is it possible to obtain samples from TI for the CC8530 or the CC8531. Currently I cannot find stock with the CC8530 and previous post have revealed that the CC8531 wont be released until FW1.2. I would like to build my boards pretty soon, but I don't want to populate them with the CC8520 because when the FW1.2 comes I will have to re-spin my boards. Any suggestion please, or will I have to bite the bullet with the CC8520!

    Thanks to TI for all the support!

    Yohan

  • Hi Yohan,

    You can get samples of the CC8530 here:

    http://focus.ti.com/docs/prod/folders/print/cc8530.html#samples

    The CC8531 will be released when FW1.2 is released! However, you do not need to re-spin your boards, the devices are pin-to-pin compatible so just replacing the CC8520 with the CC8531 is possible :-)

    -Per

  • I wonder if you could link a schematic diagram of your final circuit?