• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 64 subscribers
  • Views 597 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Thermal derating curve for TPS65320BQPWPRQ1

Kazuhiro Yano
Intellectual 940 points

I was asked about thermal derating as following from a customer.

Could you support on that?

1) Datasheet has thermal derating curve(Ta vs PD), but the customer needs "Ta vs LOAD factor%".

    Such information is available?

2) 3W is maximum power dissipation in datasheet thermal derating curve(Ta vs PD).

     Why max PD is 3W?  Please provide how it is calculated.

   

  • 0
    TI__Mastermind 31580 points
    Hi Kazuhiro-san,

    This post should be in the non-isolated dc/dc forum, I will move it for you and one of my colleagues will answer it.

    Regards

    Peter
  • 0 in reply to Peter Meaney
    TI__Intellectual 940 points

    Hello, Peter

      I don't receive any responces yet.  Could you tell me current status or  a person in charge?

    Best Regards,

    K. Yano 

  • 0 in reply to Kazuhiro Yano
    TI__Genius 9655 points
    Yano-san,
    my apologies for the late response, but the thread only now got to my attention / to the automotive forum...
    1) could you please explain what you (or the customer) refers to as load-factor? If this is referring to the use-case, it depends on the actual timings: even if the part is driven at maximum load only for a low percentage of the time, but the duration is long enough to heat up the part, it is irrelevant, and the thermal limit/maximum dissipation does apply. Please also consider that you need to add the dissipation of the switcher and the LDO.
    2) the Junction to Ambient rating is 49.9°C/W, hence the temperature increase for 3W would be ~150°C. Consequently, the 3W would already only apply for 0°C Ambient temperature, at higher temperatures, it will have to less than 3W (depending on thermal design!). In theory, at ambient temperatures below 0°CC, you may be able to dissipate more than 3W, but I strongly recommend to not design for such a use-case.
    Best regards,
    Frank