• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 28 subscribers
  • Views 726 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TPA3118D2 heat dissiapation question

Ray Buck
Prodigy 200 points

I have purchased a TPA3118 board similar to this one:

www.ebay.com/itm/TPA3118D2-Digital-Audio-Power-Amplifier-Assembled-Board-Dual-Track-25W-25W-Mono-/171356434400?pt=US_Amplifier_Parts_Components&hash=item27e5a3afe0

I put 8 ohm 40 watt resistors on both output channels. I then injected a 1 kHz tone into the left channel and ran the amplifier up to the 18 watts power level. I let the board run for 30 minutes and measured the temperature of the TPA3118. It measured 55 degrees C.


Is this a safe temperature for the device? The datasheet shows a maximum of 150 degrees C. The real world application will be for music so the average power level will be nowhere near the level I was running in my test. However, if I had driven both channels, the part may have gotten much hotter.

Also, would  anything be gained by expoxying a small heat sink to the top of the device or is the die to case heat transfer too low to help?

Thank you.

  • 0
    TI__Mastermind 37045 points

    Hi, Ray,

    This device has thermal protection built in. If the device junction temperature is too high, it will shut down and enter protection mode. Yes, adding a heat sink on the case top can help with thermal performance. A good ground plane is need for great thermal performance. More ground layers the better thermal.

    reg,

    Paul.

  • 0 in reply to user5276421
    Prodigy 200 points

    Thanks for the quick reply Paul. That addresses my concerns. The device didn't shut down during my test so I guess means it is operating within its limits. I'll try driving both channels and see if it enters thermal shutdown. If it does, I'll add a small heatsink to the top of the part to see if it prevents shutdown. Of course this won't be a problem in the real world application but I am curious about behaviour at full power for an extended time. 

    The existing board has some ground plane under the device on the top layer. There is the suggested through hole pattern underneath the pad similar to the design shown in the TI evaluation board manual. Also, virtually the entire bottom of the board is a ground plane so that helps with heat dissipation.

    Thanks again for your help.

    Ray