• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 215 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: Ground plane area required for achieving R(theta-ja) specified in the datasheet

Surya Mohan
Prodigy 160 points
Part Number: TPS7A49

As specified in the datasheet of TPS7A49, the R(theta-ja) of DRB (VSON) package is 47.7 deg C/W.

Please let me know the area of ground plane required for achieving the above R(theta-ja).

  • 0
    TI__Genius 10490 points

    Hi Surya,

    The R(theta-ja) specified in the datasheet is derived from the industry standard JEDEC High-K Thermal Test Board described in JESD51-7. This is a four layer PCB in which the only connected ground plane is a 1 oz copper internal layer with an area of about 5500 mm^2. There are no planes on the outer layers, and the second internal layer is left unconnected.

    Furthermore, note that the DRB package has a thermal pad. The separation of thermal vias within the thermal pad (1.2 mm spacing) is also standardized by JEDEC in JESD51-5. The test board used to obtain R(theta-ja) places as many thermal vias in the thermal pad as possible while still following this standard. You can freely register to access JEDEC standards here:

    https://www.jedec.org/user/register

    Thanks,

    Gerard Copeland