TPS54360: TPS54360 PIN SW short to GND problem

Hi

1. do you know it is damaged in stable statues or in Line/Load transient?

2. what's the saturation current of inductor? is it higher than OCP point of chip?

3. did only chip damage or any other component damage?

4. do you have layout to share

Thanks

Hi Daniel Li14,thanks for your replay.

Here are some infomation for you:

1.The IC damaged in stable statues, the input voltage is 24V DC;

2.The inductor is SLF7055T-220M1R7-3PF from TDK, Isat > 2A from the datasheet:

3.Only chip damaged,when re-weld a new one,the PCBA work ok again;

4.Top and bottom layout as below:

the PCB is 8 layer, L2 and L7 are GND plane.

HI

the damage may happen due to overvoltage or in some unexpected condition. you may need test the SW waveform with the system. see any abnormal system transient at input and output which may make the SW overshoot then damage the chip.

another point is the input L,C which close to inpt pin , you have a 36V zener to protect the chip, but in some case, the LC may resonant which cause a overshoot voltage at Vin pin. it just my guess, so stronge recommend you check the chip with system working conditon. 

Thanks

Daniel Li