LM5175: LM5175 HDRV1 Pin damaged by hot swap

Hi,

Thank you for using the LM5175.  Can you share your schematic?  Also, can you monitor the input voltage at the SW1 during hotswap, so we can see if there is possible over voltage transient that may kill the high side driver?

Thanks,

Youhao Xi,  Applications Engineering

Hi Youhao

Schematic as below.

I find the same thing happens when OCP

May I ask your to post the schematic NOT in upside down?  I am not able to rotate it for a review, unless I have to turn my head downward. 

What do you mean by "the same thing happens when OCP"?  Can you be more specific?

Thanks,

Youhao

schematic update as below. 

SW1 in normal as below.

Hi ,

What is the waveform? Under what condition?  I would like to see the SW1 and Drain voltage of Q6 during hot swap.  Both SW1 and Drain of Q6 should be referenced to PGND node.

Please show both the zoomed out (overwiew) and zoomed in (detail) waveforms.

Thanks,

Youhao

Hi，Youhao.

     This is the waveform I captured in the ocp state.

But the waveform in the event of HDRV1 failure can not be captured.

The first waveform is the sw1 waveform after failure.

      And I find that the issue occurs after the PIN(EN)  is connected to the MCU.

I cannot understand why ?

      Please HLPE!

Hi 

Is the yellow SW1? Where is the drain voltage of Q6?  I would like to see if there is any over-voltage transient that could kill the high side driver, but your waveform is not clear what is what, and also not details of the switching transient.  I really want to help but the info provided is not enough.

Thanks,

Youhao