• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 179 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.

Original question:

TLV760: Can TLV76012 works in a longtime 'on-off-on-off......' mode?

TLV760: TLV760

Maria Jose Pazos Salgado
Prodigy 10 points
Part Number: TLV760

I need to calculate the junction temperature of the TLV76012 component in my application. I have measured the temperature on package top with an IR camera, and it is 84 ºC at an ambient temperature of 20 ºC. The component dissipates 0.8 W and is mounted on a 0.7 mm thick, 2-layer board. The board is also mounted on a large heat sink. I think the Jedec thermal resistance provided in the datasheet of 2.9 ºC/W may not correspond well to my application. Therefore, I would perform the calculation using the Rjc of 92.9 ºC/W.

So the calculation would be: Tj= 84ºC + 0.8 W*92.9= 158.3 ºC, so it might not work correctly.

However, using the Jedec thermal resistance, the calculation would be: Tj= 84ºC + 0.8 W*2.9= 86.3 ºC, so I could use the component.

Which thermal resistance value should I use?

Comparing with the Jedec, isn't the value of 92.9 ºC/W too high? Is that value correct, or is it an error in the datasheet?

  • 0
    TI__Genius 14245 points

    Hi Maria, 

    If the heatsink attached to the board also has a good thermal connection/path to the LDO on the board then I agree the Standard JEDEC thermal numbers may not be very applicable to your situation. One thing that indicates that your board is better at dissipating heat than the JEDEC standard is the fact that you are operating the device with 0.8W @ 20C in your application and you are not seeing it go into thermal shutdown. 

    Thermal dissipation is very dependent on PCB layout, so in this case I would recommend testing the thermal dissipation of your actual board. We have an explanation of how you can do this in the lab in our [FAQ] Thermal Dissipation From an LDO Perspective, which is described for Question #6 in the FAQ. 

    I hope this helps.