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DRV8412: Temperature increase with 1sec operation

Part Number: DRV8412

Hi all

Would you mind if we ask DRV8412?
Please refer to the attachmentfile, and could you give us the reply?
20180821_DRV8412.pdf

Kind regards,

Hirotaka Matsumoto

  • Hello Matsumoto-san,

    We don't have an easy and fast way to simulate thermal transients like this. If the chip has enough time between pulses to cool to room temperature, then the temperature rise should not be significant since the device does not drive high currents for a long time. However, if these pulses occur regularly, then you can calculate the average current and find the temperature rise from that.
  • James san

    Thank you so much for your reply.

    OK, we got what you mentioned.

    If you have some advice for our additional questions(as follows), could you give us the reply?

    However, if these pulses occur regularly, then you can calculate the average current and find the temperature rise from that.
    ->So, when we calculate the average current, we should consider current × time =areasquare measuresize.
       Therefore, about saturation time of radiation of heat, generally, is it possible to guess it?
       Does it depend on the board layout?

    Kind regards,

    Hirotaka Matsumoto

  • Matsumoto-san,

    Yes, to calculate the average current, you find the area under the current vs. time curve for one whole period of your pulses, then divide by the time of the period. In the PPT you shared, if the cycle repeats every 5 seconds, then I would calculate the average current by (5.8*1+2.3*1.5+0*2.5)/5 = 1.85 A.

    Board layout will impact heat dissipation, The more copper under and around the device, the better thermal performance it will have. If you use the thetaJA number, then you are assuming the conditions for thermal dissipation are identical to the test board or test simulation. The URL below will take you to a page where we have collateral on thermal analysis and calculation.

    www.ti.com/.../midlevel.tsp
  • James san

    OK, thank you so much for your reply!

    Kind regards,

    Hirotaka Matsumoto