LMR14030-Q1: Failure scenarios

Sandhya Jetti

Intellectual 535 points

Part Number: LMR14030-Q1

Hello,

Under what conditions does high side mosfet fail short? Vin -Vsw becomes short (~8-10 ohm).

over 4 years ago

0 Orlando Murray over 4 years ago

TI__Mastermind 22299 points

Hi Sandhya,

The most frequent cause of high-side MOSFET damage is when there is negative current from SW to VIN that conducts through the body diode and causes damage.

This happens when VIN is below VOUT, and can be due to a shutdown where a large COUT output capacitor holds the output voltage for a longer time than the VIN falling, and the capacitor conducts reverse current from VOUT to VIN.

Please be sure the output voltage is drained before (or along with) VIN voltage, otherwise you may have to insert a low drop blocking diode at the input of the converter.

Hope this helps,

-Orlando