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CC1310: What's the meaning of IB in CMD_SET_TX_POWER command?

Part Number: CC1310

Hi,

What's the meaning of IB?

Usually, SmartRF Studio7 recommend this value to IB. Customer don't need to write it.

1. But if it has hardware tolerance on customer boards, like PCB manufacture, components. Is it possible rewrite this value to IB at 25'C so that compensate boards tolerance?

2. In default, temperature compensation is enable or disable?

It seems disabled according this thread: e2e.ti.com/.../2253422

  • 1) They can do it but I would advise to use the PA table from SmartRF Studio. In production test, if they see that the 10 dBm setting gives 1 dB too high or too low value, use the 9 dBm setting or 11 dBm setting instead.

    2) The txPower values given in SmartRF Studio is given with a non zero value in txPower[15:9]. Based on the thread you link to, why do you thing temp comp is off default?
  • Hi TER,

    1. What's the PA table? Is it the value on below red box? 

    For example, 10dBm is too high or too low. What's the minimum value to adjust? +-1dBm?

    2. If it already has temp compensation, why measure high and low temp to do compensation by 3 step on that thread?

  • 1) Yes
    2) As you can see from the thread, the steps are valid if the customer for some reason want to make a PA table based on their hardware.

    The PA table we have made has 1 dB steps. For output powers > 0dBm it could be possible to have a table with smaller steps but we haven't made this since the variation from sample to sample could be in the 1 dB range and hence using smaller steps would not have any upside.
  • 1. I see the IB[5:0] is 6 bits. Can I use IB to do output power adjust? 1dB step is too big to be used for fine tuning.

    txPower[15:9]: temp coefficient
    txPower[8]: TX BOOST bit
    txPower[7:6]: Gain
    txPower[5:0]: IB

    2. Usually, customer don't need to measure temp for compensation except it has some big difference on their hardware. Right?
  • 1) Yes, IB is used to adjust the output power.
    2) As the link to the old E2E post in your first post show, the temperature compensation value is only valid for a given IB. If your customer changes IB and still want temperature compensation they have to follow the steps given to calculate the temp compensation for this IB.
  • Hi TER,

    Great!
    Last question, what's the minimum adjustable value? +-1dBm or 1/64 because IB is 6 bits [5:0] ?
  • Neither. For high output levels the PA is in saturation and changing IB +/- 1 bit will have low effect. For low output levels the PA is not in saturation and a change of +/- 1 bit could give more than 1 dB.