• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 63 subscribers
  • Views 242 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.

UCC256303: Thermal management of IC

yogendra Sharma
Prodigy 70 points
Part Number: UCC256303

Hi Team,

We are using UCC256303 in our LLC design; and it is getting heated up (upto 65deg C at 27 deg C ambient).

I am looking for the ways to cool that down.

1. Is there any pin which can be connected to bigger plane (for heat conduction)?

2. Can we give external 12 volt regulated supply to run gate drivers instead of using RVCC pin of IC; if yes, then how?

3. Any other effective method to reduce the IC temp?

Regards,

Yogendra

  • 0
    TI__Mastermind 27105 points

    Hi Yogendra,

    Thanks for reaching out. What is the voltage applied to VCC? One possibility is to step down the voltage applied to the VCC pin to be something much closer to 12V to make the internal LDO that generates RVCC to be more efficient.

    Best Regards,

    Ben Lough

  • 0 in reply to Benjamin Lough
    Prodigy 70 points

    Hi Ben,

    VCC pin voltage: 15Vdc

    Regards,

  • 0 in reply to yogendra Sharma
    TI__Mastermind 27105 points

    Hi Yogendra,

    Thanks for the information. We could look at stepping down VCC down to 12V. The internal LDO would work more as a "pass-through" but this is ok to do and would help reduce some of the heat in the package. You could also experiment with larger gate resistance for the high side and low side. This will shift some of the driver losses to the gate resistance and out of the IC. The gnd pin would be the preferred choice to connect to a larger ground plane but given the IC package I am not sure if this is will result in any improvement in the thermal management. Using smaller Ciss MOSFETs would also help reduce the driver loss and reduce the IC temperature. I don't see a reason why an external, well regulated 12V could not be bootstrapped to provide the high side bias but I must caution this has not been done before to my knowledge. I would suggest trying some of the other suggestions first before considering attempting this.

    Best Regards,

    Ben Lough