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RF430FRL152H: RF430FRL152H Temperature problem

Jan Slapsak
Prodigy 160 points
Part Number: RF430FRL152H
Other Parts Discussed in Thread: TRF7970A,

Hi,

in past months i have been developing hardware for some temperature and humidity measurements using RFID. Reader part consist of MSP microprocessor and RFID transciever chip TRF7970A, while the sensor part includes some digital sensors that are connected via I2C to RF430FRL152H transponder.

The whole system works great except when i start to increase temperature. The RF430FRL152H chip does not respond when temperature exceeds 60°C. In the datasheet is stated that maximum operating free air temperature is 70°C which would be exceptable for our appplication but 60°C it's a little bit too low. I also read on forum (HERE) that one was able to measure temperature at around 80°C.

My question is what can i do about it? Does the chip shutdown itself when reaches 70°C or it works further on? What can be done if it turns of at 60°C?

Thanks for you reply.

Best Regards

Jan Slapšak

  • 0
    TI__Guru*** 128255 points
    Hello Jan,

    I wouldn't expect the device to shut off at 60 degrees C, but I could see degraded performance in terms of RF occurring. When you say the chip does not respond, do you mean to RF commands?

    Can you see if the I2C bus is still functioning as expected?

    Is the chip RF powered or powered via battery or other source?

    What read range are you observing the issue at? If you reduce the read range, do you get any RF communication?

    How many boards have exhibited this failure?

    Are you using a custom board or the RF430FRL152HEVM?

    If a custom board, what are the antenna sizes for both reader and tag? What is the reader antenna tuned to?
  • 0 in reply to Ralph Jacobi
    Prodigy 160 points
    Hi Ralph,

    I am using custom board with antenna sizes described in your documents, so dimensions are the same.
    The chip is powered via RF field. and it's working fine unitl around 60°C where there seems to be thermal shutdown. The temperature inside the chip shouldn't be much more than 60°C because it doesn't receive enoguh power over RF field.
    Reading range is less than 1cm. This occured on all of prototype boards unitl now (4 were made).

    I measured the RST pin and it wass oscillating. It seems like it turns on, checks the temperature and then resets itself.

    Best Regards,
    Jan Slapsak
  • 0 in reply to Jan Slapsak
    TI__Guru*** 128255 points
    Hello Jan,

    Thank you for providing these details. At 1cm read range the device should operate fine. I have sent this issue and some inquiries to the systems team, but it may be a couple days for them to investigate and report back. If I have a chance this week I also will try to test the EVM in a temp chamber to see if I can replicate any such behavior.
  • 0 in reply to Jan Slapsak
    TI__Guru*** 128255 points
    Hello Jan,

    I'm still trying to get feedback for you... the design engineer is, as you might understand, assigned to different projects now, and so it is a challenge to get this looked at with sufficient detail in a short amount of time.
  • 0 in reply to Ralph Jacobi
    Prodigy 160 points

    Hello Ralph,

    Thank you. I will be back in my office next Monday. Hopefully there will be some response from design engineers by then.

    Best Regards,

    Jan Slapsak

  • 0 in reply to Jan Slapsak
    TI__Guru*** 128255 points
    Hello Jan,

    I was informed that the timetable for investigation is likely two weeks out. It potentially could be sooner, but unlikely.
  • 0 in reply to Ralph Jacobi
    Prodigy 160 points

    Hello Ralph,

    Ok and thank you for information. We'll wait in the mean time.

    Best Regards,

    Jan Slapsak

  • 0 in reply to Jan Slapsak
    Prodigy 160 points

    Hello Ralph,

    is there anything new from the system team about described problem? I am still waiting for any answers that would help us to finish our design.

    Best Regards,

    Jan Slapsak

  • 0 in reply to Jan Slapsak
    TI__Guru*** 128255 points
    Hello Jan,

    I still have not received any feedback. I will try and get another time estimate by next week...
  • 0 in reply to Jan Slapsak
    TI__Guru*** 128255 points
    Hello Jan,

    I haven't gotten anything back still.

    Whats the status on your end? Is this an open issue still or have you moved on?
  • 0 in reply to Ralph Jacobi
    Prodigy 160 points

    Hello,

    Yes, this is still an open issue. It is in great our interest that you'll provide us with some useful information regarding the temperature dependency of an RF430FRL152H. Otherwise, we will need to consider building a new system with components provided by other manufacturers.

    Best Regards,

    Jan Slapšak