• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 64 subscribers
  • Views 1386 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.

TPS7A4901 cycles on and off

Sunglin Chen
Expert 2335 points
Other Parts Discussed in Thread: TPS7A49

Hi,

I use a TPS7A4901 to design a 24V to 3.3V circuit which was attached. The load was about 120mA. It cycles on and off after 2 or 3 seconds when power on. I would like to know anything wrong with my circuit. Does anyone have the same issue?  How to achieve my requirement that to design a 24V to 3.3V circuit with a maximum load of 150mA.  Thank you.

Sunglin.

  • 0
    TI__Expert 8905 points
    Hi Sunglin,

    It sounds like you are entering thermal shutdown. Using the TPS7A49 in the conditions described, you are dissipating ~2.5W across the device, which comes out to a temperature rise of ~160C worst case - this will cause the part to shut itself down to prevent damage to the IC.

    I would advise a buck converter and post-regulate the buck converter with an LDO if needed.

    Regards,
    David
  • 0 in reply to David Hopkins
    Expert 2335 points
    Hi David,

    Yes, you are right. The thermal pad is very hot and it did enter thermal protecting mode. I will try to use other components. Thank you.

    Sunglin.