• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 468 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.

TPS7A49: Use of TPS7A49 LDO in potted cabinet

Surya Mohan
Prodigy 160 points
Part Number: TPS7A49

We are designing a PCB which would be enclosed in a cylindrical plastic cabinet and would be filled with a potting material having thermal conductivity of 0.45 W/m K.

We are using TPS7A49 LDO (VSON-8 Package) to convert 15V DC to 5V DC @ 30mA load current. Operating temperature range of circuit varies from -5 degC to +60 degC. 

For good power dissipation, through this LDO, should we remove the green masking material (thermal conductivity of green masking material is 0.2 W/m K) from the ground plane which is below the LDO?

Would there be any significant contribution of masking material in decreasing heat flow from Copper to the potting material?

  • 0
    TI__Guru 55940 points

    Hi Surya,

    Your layout is a good example of maximizing the GND copper local to the LDO.  This will benefit your application since the primary heatsink for the LDO is the GND copper in the PCB.  Below is our recommended land pattern which is appended to the end of the datasheet.  We do recommend exposing the GND copper directly under the LDO as the GND plane connection to the thermal pad of the LDO is the primary path for heat.  

    Very Respectfully,

    Ryan