• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 224 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.

OPA1678: OPA1678IDRGR Thermal Considerations

Michael Aubin
Prodigy 10 points
Part Number: OPA1678

Tool/software:

I have a design with an OPA1678IDRGR and it's running much hotter than expected and also pulling significantly more current than expected when compared to simulation. I noticed that I missed the 4 vias on the thermal pad that are recommended in the datasheet for this specific package.

Can TI confirm if this part does need vias in the thermal pad for proper thermal relief? It's not noted in the layout guideline section or power dissipation section.

  • 0
    Prodigy 10 points

    Also, I could not find a graph on the datasheet detailing junction temperature vs supply current. We expect to see ~9mA of current on the positive supply and are seeing ~40mA. Our operating points match simulation, so I was wondering if TI had any more information about junction temp vs supply current that they could provide.

  • 0 in reply to Michael Aubin
    TI__Mastermind 25250 points

    Hey Michael, 

    What potential is the thermal pad connected to? The vias are optional and you may use vias if your layout needs them to route traces. The vias should be plugged or tented. The thermal pad must be tied to Vee and ideally connected to the Vee plane for best thermal performance. 

    We don't have a graph for temperature vs supply current. We have a thermal section on our Ti Precision Labs however that would help guide in the calculations. 

    This can be found in the Power and Temperature section in the link below:

    https://www.ti.com/video/series/precision-labs/ti-precision-labs-op-amps.html

    Best Regards, 

    Chris Featherstone