Hello,
We have are using a LT4359 as a 24V load switch with reverse input protection with a current up to 10A. Our circuit is shown below and follows the design in DC1676A demo board.
In general the circuit works perfectly. However, we have seen a few failures of Q2 (from datasheet, Q10 (in our circuit) - the load switching NMOS - where the RDSon resistance increases meaning we are dissipating over 30W in the NMOS device which then introduces a significant voltage drop across the NMOS. NMOS is BSC050N10NS5ATMA1
The fault seems to occur when we are operating at 10A and the Vout (Vin for LTC4359 circuit) fails and turns off. We have not been able to capture the gate and source voltages on an oscilloscope when the fault occurs as it happens very infrequently.
My assumption is that the Vgs voltage is going out of the NMOS spec and damaging the device.
Do you have any advice on additional protection which could be added to the gate of the load switching NMOS gate to try and prevent this failure? Or is there something else I am missing which is causing the failure?
Thanks
