Other Parts Discussed in Thread: LM74930
Tool/software:
Hi,
I used LM74930-q1 to work as a high side switcher (with OV,UV, OC protection), during the testing, I found a problem on the board, the HGATE MOSFET will be very easily damaged under below testing set up:
1, I connected an external DC power supply with the board as the DC input, the DC input voltage is 48V
2, I connected a e-load to the output of the board, set e-load in CC mode.
3, I set the e-load to draw 500mA current from the output of the board.
4, turn on the e-load
5, Then power on the external DC power supply, after the board is bring up, the software will set the EN pin of M749030-Q1 to high to turn on the HGATE MOSFET.
6, Then I found the HGATE mosfet was damaged, the Drain and Source of MOSFET was short.
But if I do the testing setting with the different test sequence as below, the circuits works fine and mosfet works fine.
1, I connected an external DC power supply with the board as the DC input, the DC input voltage is 48V
2, I connected a e-load to the output of the board, set e-load in CC mode.
3, power on the external DC power supply, after the board is bring up, the software will set the EN pin of M749030-Q1 to high to turn on the HGATE MOSFET.
4, I set the e-load to draw 500mA current from the output of the board.
5, turn on e-load to draw current from the board output.
Would you help to explain why the HGATE MOSFET was damaged with minimum load during start up?
Thanks
