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CC1125: cc1125 + skyworks 1W amplifier - sensitivity

Idan Atia
Intellectual 270 points
Part Number: CC1125

Hi TI team,

I disigned a PCB card with the reccomanded 1W amplifier as the reference said:

I chose with RF Studio the parametrs as noted at the data sheet to get -129dbm sensitiviry (300bps, 1 or 4khz deviation (both tested, 4 is better), 15.6 RX filter).

Nevertheless, I got -120dbm sensitivity (after I checked the attenuators and checked the power of the transmited data).

I use 2 similar boards to test it and a success test is when 50 times the data goes back and forward.

I wonder if you have an idea why I didn't acheive -129dbm (or at least -125..).

thank you!

  • 0
    TI__Guru**** 317180 points
    - Which packet length do you use? Note that we use 3 byte payload, fixed length for out measurements.
    - Note that the sensitivity number for 300 bps in the datasheet is for 3.8 kHz channel bandwidth. By increasing the bandwidth to 15.6 kHz you loose some dB.
    - Have you ensured that you have very precise frequency? In a narrowband application the frequency tolerance has to be small.
    - I have tried to measure sensitivity with attenuators and I have had trouble getting the correct results because:
    - Some of the power goes over the air (the receive board has to be shielded)
    - Unforeseen insertion loss
    We use a signal generator where the signal path is calibrated with a VNA to get accurate results.
  • 0 in reply to TER
    Intellectual 270 points
    OK! thank you - the RX filter BW has been changed to 3.551 KHz and it OK :)
    thank you