BQ51050B: CAlibrating RX FOD with bq500412EVM-584

Part Number: BQ51050B

Hello,

We are using Texas Instruments Qi charging receivers to develop wearables, and other sensors, with Qi charging capabilities, and we would like to clarify some points about the FOD calibration of the RX side.

We have searched for information on how to perform this calibration and we found a couple of videos from Dick Stacey in the TI Training website where this issue is explained (training.ti.com/wireless-power-101-fod-lab-session). Our question is about the tools used to perform the calibration. In the video it is referred the use of the "AVID Technologies Qi FOD transmitter", but this tool is too expensive for our current budget. What I would like to ask is if we can use the Texas Instruments bq500412EVM-584 (which we already have at home) along with the "bqTESLA TX Tuning Tool Software for FOD set up" referred on the evaluation module data sheet.

If yes, were can we find the bqTESLA TX Tuning Tool Software for FOD set up, and documentation on how to use it?
If not, why cannot we use the bq500412EVM-584? Are there any alternatives to the AVID Technologies Qi FOD transmitter?

As a last remark, I will just note that the sensors are not going to be Qi certified.

Thanks,

Carlos

  • Hello
    You are not doing a Qi certified system but will you build both RX side and TX side? Will they only be used together?

    The bq500412EVM-584 (standard TX) cannot be used to calibrate RX FOD and replace the AVID Technologies QI FOD transmitter.
    Also the Standard RX cannot be used to calibrate the TX FOD.
    If you are building RX and TX that will be sold and used together it may be possible to align FOD settings on the two units so they work well together.

    Best Regards,

    Bill Johns,  Applications Engineer

    Texas Instruments Inc

    Dallas, Texas

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  • In reply to Bill Johns:

    Hello,

    We will only build the RX.
    Do you know a cheaper alternative to the AVID Technologies QI FOD transmitter?
    What makes it different from the bq500412EVM-584, or other similar device, to be the device to use for this calibration?

    Thanks,
    Carlos
  • In reply to Carlos Resende:

    Hi Carlos
    If you build only the RX it will and rely on customers to purchase a TX then your RX unit will need to have a good FOD calibration run on it.

    Do not have alternative for AVID FOD TX. You may check with them they may offer an FOD calibration service for less.

    Best Regards,

    Bill Johns,  Applications Engineer

    Texas Instruments Inc

    Dallas, Texas

    Note:  If this answer solves your question please click the "Verify Answer"  button.

  • In reply to Bill Johns:

    Hello Bill,

    Following your inputs we bought the AVID FOD TX to calibrate our Qi device based on the BQ51050B. We have downloaded the Foreign Object Detection (FOD) Calibration/Tuning Tool (Rev. A) available on the BQ51050B software resources page, and we have been trying to use it to perform the calibration. However, the tool is not allowing to iterate with 0.1mV over Vos as specified in the manual. It just allows us to iterate with 1V differences. If I put, for example, 12,3mV and press enter, the tool just changes the value to 0 and does not change the model error map. However, if I put 12mV the tool behaves as expected. This behaviour also occurs if I use as input file the example distributed with the tool.

    Can you help us on this? With this issue we are not able to tune our sensor...

    Thanks,

    Carlos

  • In reply to Carlos Resende:

    I am checking on this and will try to have an update today or tomorrow.

    Best Regards,

    Bill Johns,  Applications Engineer

    Texas Instruments Inc

    Dallas, Texas

    Note:  If this answer solves your question please click the "Verify Answer"  button.

  • In reply to Bill Johns:

    Hi Carlos

    We tested the Tool here and did not see a problem with Vos window.  Set value to 12.3mV and could step in 0.1mV increments.  Tested on two separate PCs.

    So things for try:

    1.) Try the up / down arrow buttons to change value in.

    2.) Do not use "," only use"." the system will not recognize "12,3mV"  

    3.) Can you send a scree shot of the screen when the problem occures

    4.) Verifiy that you have version 1.0.1, located under "Help" -- "About FOD Cal..."

    Best Regards,

    Bill Johns,  Applications Engineer

    Texas Instruments Inc

    Dallas, Texas

    Note:  If this answer solves your question please click the "Verify Answer"  button.

  • In reply to Bill Johns:

    Hello Bill,

    Thanks for your reply. In the mean time I was able to solve the issue. It was related with the regional settings of my laptop. It was configured to use the "," as decimal point instead of the ".".

    In the mean time I was also capable of performing 2 calibration sessions, but I'm getting very strange results, as they are far from going to a calibrated solution (attached to the post I'm sending the txt with the values I measured in the 2 session - FOD_DATA01 and FOD_DATA02, and the final calibration of the session 1 - FOD_CALIBRATION01, that was used to configure Ros and Rfod of session 2).

    Regarding my calibration circuity, as I do not have a battery simulator I used the solution suggested by  Texas here: www.ti.com/.../slva618.pdf

    Still about the battery, the guidelines available on the FOD calibration manual and video are for non charging ICs. However, the BQ51050B is a charging IC. Considering this, the current referred as Iload considers the current flowing to the battery simulator, or just the current of a load appended to the BQ51050B output in parallel with the battery (the former possibility was the one I used for calibration)? Also, the starting point Iload=0mA does not represent 0mA flowing out of the BQ51050B, as there will be some current going to the battery simulator, right?

    Thanks,

    CarlosFOD_CALIBRATION01.txtFOD_DATA01.txtFOD_DATA02.txt

  • In reply to Carlos Resende:

    Hello Bill,

    Were you able to take a look to this issue? Do you have any comment on it?

    Sorry for annoying you with this, but we are dependent on this to go with our client for the production of sensors to a major pilot test before going to final production.

    Thanks,
    Carlos
  • In reply to Carlos Resende:

    Hi Carlos

    Sorry for the delay we are trying to set up to repeat the test here but have run into delays due to equipment and personal.

    We did try to use the file that you sent and it has a problem, it looks like something is going wrong during the file generation.  will try to update you again today.

    Best Regards,

    Bill Johns,  Applications Engineer

    Texas Instruments Inc

    Dallas, Texas

    Note:  If this answer solves your question please click the "Verify Answer"  button.

  • In reply to Bill Johns:

    Hi Carlos
    Something is wrong with the set-up or data, as current is increased we should see the PPT and PPR both increase but they are flat from 100mA to 200mA. The problem may be the battery emulator.
    Another battery emulator to look at is in the bq24040 User's Guide:
    www.ti.com/.../sluua77.pdf

    Current measurement should be all current out of the bq51050.

    Best Regards,

    Bill Johns,  Applications Engineer

    Texas Instruments Inc

    Dallas, Texas

    Note:  If this answer solves your question please click the "Verify Answer"  button.