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CC1120: Transmission delay issue

Part Number: CC1120
Other Parts Discussed in Thread: CC1125,

Hi team,

Here's an issue from the customer may need your help:

When receiving packets from the CC1125 using the CC1120, the transmission delay increases by approximately 1000 ms (compared to the CC1125 receiving and the CC1125 transmitting).

The customer would like to know what's the possible cause of this issue. Could you help check this case? Thanks.

Best Regards,

Cherry

  • Hi Cherry,

    A couple of questions:

    • What PHY settings are being used on the RX/TX devices (and are they same same on the RX/TX devices)?
    • Is this using custom hardware or a TI EM?
    • Are there any differences between the hardware used for the CC1120 and CC1125 (that the customer knows of)?

    The CC1125 is a narrowband version of the CC1120, and the CC1125 is also able to run on a 40 MHz XTAL (which gives somewhat lower phase noise). There aren't many differences between the two devices besides that.

    Regards,

    Zack

  • CC1120 and CC1125 behave exactly equal if the same settings and external componnets are used. a 1 s delay is a lot. Is the code used for the CC1120 vs CC1125 the same? It sounds like the fw running in the two cases are far from the same.

  • Hi Zack,

    Thanks for your support.

    On h/w, the devices used for comparison testing on the receiving side (CC1125 and CC1120) do not have transmit channels (receive only, not transmit data).

    The design is as transcever+saw+LNA.

    The difference is that the CC1120 is a 32-MHz crystal and the CC1125 is a 40-MHz crystal.

    Is this case related to the RX Sniff Mode CC1120?

    Thanks and regards,

    Cherry

  • Hi,

    May I know is there any update?

    Thanks and regards,

    Cherry

  • Hi Cherry

    Please provide info regarding what register settings/PHY you are using in the two cases, what packets you are sending, and how/where you are measuring this delay. 

    Siri