• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 315 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.

LM5069

bill schmitz
Prodigy 10 points
Other Parts Discussed in Thread: LM5069

I have a problem where my LM5069 fails shorted, Vin to Gnd.

I am using this as an inrush control for the front end of a power supply. I am not measuring input current, I am just using it as a charge pump to ramp up and saturate a pass FET.

Sometimes, after an inrush event, the fails short. The FET does not fail. Replace the IC and it all works as expected.

My testing is being done at 60VDC input. I have a large 60V power source, I quickly connect the power source to my power supply input and monitor inrush with a current probe. Then I disconnect the power source by pulling the wire off the terminals. I think this is a good representation of a hot swap input.

I do have a 100 ohm resistor from Vin to drain of the pass FET, and a 68V zener from Vini to ground. This is to protect from input transients

  • 0
    TI__Genius 12380 points

    Hi Bill,

     

    How are you testing this circuit and what level of protection are you trying to accomplish?

    We would recommend using our EVM for initial testing and making modifications as necessary. We do not recommend running this device without a SENSE connection.

    As for protection for VIN, we recommend the SMBJ70A, which is used on our EVM. What zener are you using, and what current are you testing it at?

     

    Thanks!

    Alex