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TLIN2029-Q1: extended temperature range

Part Number: TLIN2029-Q1

Dear all,

one of my AA would use the TLIN2029-Q1 in truck application where the ambient temperature can reach 140degC.

The device will work 1/10 of his life (life time 30000 hours) at 140degC.

Do you have any suggestion ?

regards,

Domenico

  • Domenyko,

    Though the ambient temperature will have an indirect effect on the overall lifetime of the device, the more important factor will be the junction temperature of the device. Current consumption will play a big factor in the junction temperature, so the amount of time the device is in an active state will increase the junction temperature, and thus shorten the overall lifespan.

    Since heat is the main factor, sinking the heat on the board away from the LIN transceiver will be key. Creating a strong ground connection with a ground plane of full copper will help with this, and in general have large copper traces and pours for power connections will help sink the heat to the board and out of the transceiver IC.

    Taking advantage of the device's low-power modes will also help to reduce current consumption and thus heat generation from use. Any time the device isn't active for an extended period of time, switching to Sleep mode will help with this.

    Regards,
  • Hi Eric,
    thanks for the suggestions. So unless the Tj is below 150degC the device should work but the lifetime will be impacted due to the operation outside the recommended operating conditions.

    regards,
    Domenico
  • Domenyko,

    That is correct, and since the ambient temperature is going to be 140C, it will be hard to avoid the transceiver losing lifetime. The best suggestion is to pull as much heat away from the transceiver as possible using the methods I mentioned previously. This will at least extend the lifetime for as long as possible within the harsh conditions of the application.

    Regards,
  • Domenyko,

    We also have DPPM/FIT rate data here and a temperature derating tool here.

    Regards,

  • Hi Eric,
    thanks for the extra information end the tools.

    regards,
    Domenico
  • Hi Eric,

    from the DPPM tool the failure rate at 140degC is 152ppm, but is there any way to evaluate how many failures in 30000 operating hours ?

    Moreover is there any method to evaluate how many hours the Transceiver can work (operative) at 140degC ?

    regards,

    Domenico

  • Domenico,

    Thank you very much for your patience on this one.

    At 140C, this device has a FIT rate of 35.0. FIT is the number of units failing per billion operating hours, which means that the TLIN2029-Q1 has 35 units fail under the given conditions. The MTTF under 140C is 2.86e7, meaning the mean time to failure would be ~29 million hours for one unit.

    All of this being said, since this is outside the tested temperature range of the device, we can't guarantee the reliability of the device in 140C operating condition.

    Another thing to note is these calculations are based on a specific sample size and probability formulas with an acceleration factor based on the tested temperature and the operating temperature. So according to the probability curves, the FIT rate is 35.0, it doesn't mean through this testing 35 units failed.

    Regards,

  • Hi Eric,

    thanks for the explanation.

    Regards,

    Domenico