TPS7A49: TPS7A4901 is broken, but we canot find the reason

Hi Frank,

Is the issue the peak to peak voltage on Vout? If so can you provide a scope capture more zoomed in? Ideally showing the frequency of the ringing. Also can you remove your load and try to see if output stabilizes - there could be a path through your load.

Could you provide more details on the over-voltage condition you mentioned?

Thanks!
David

Hi David，

I have asked the ripple from the customer . But the max voltage will not reach the datasheet maximum. Can it be broken?Thanks.

Hi Frank,

Sorry I'm still a bit confused on your problem- is the maximum voltage that cannot be reached on the input or output?

-David

Hi David,

I mean even the input have ripple, but it isn't above 36v. So it should not break the device. Thanks.

Hi Frank,

That should not break the device, unless Vout exceeds Vin for a significant amount of time, which would cause reverse current damage. Your shutdown waveforms look like this could be happening.

Regards,
David

Hi David,

The customer tested the board again, no werid phenomenon happen. Do we think the failures can only be caused by the over voltage or output voltage higher than input voltage. Thanks.

BR

Frank

Hi Frank,

It can cause problems, especially if the voltages exceed abs. max. Likely this was just a measurement issue like a bad ground connection or environmental noise.

Regards,
David