• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 615 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.

LM25117: LM25117 Overcurrent protection mode question

Sulyn ZHANG
Expert 8700 points
Part Number: LM25117

Hi team,

My customer now is testing our LM25117. However, they are some questions when test the Overcurrent protection mode, can you help to check, thanks a lot.

Below is the schemactic that customer used.

Schematic.zip

For normal overcurrent, for example 11.5A Overcurrent situation as below, the hiccup mode works normally as below tested waveform:

Yellow color is the output voltage, green color is the current, the Hiccup interval was set to 125ms which is correct.

When Customer try to short the Output to GND, then the Ishort will become bigger, then they got below waveform that can't understand, can you help explain because We can't find the description it in datasheet for this waveform:

Yellow color is the output voltage, green color is the current. But the re-start interval become 3ms and didn't go into Hiccup mode, can you help check this, thanks a lot!

Sulyn Zhang

Best regards,

  • 0
    TI__Mastermind 39980 points
    Hello Sulyn,

    Can the customer check the Voltage across the CRES. As there could be noise on this pin. If the noise is large enough, it could trigger a premature restart?

    Also suggest taking a scope plot of the VCC in order to check at no time during the Hiccup off time, the VCC UVLO has not been reached?

    Thanks.

    Kind regards,

    David Baba.