Tool/software:
Hello everyone here, this is my first time in a E2E forum, initially i was seeking for any solution for random FET failures with TPS48111 driver and 2 days ago I found this thread which is also mostly describes my issue -> https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1454329/tps4811-q1-random-short-mosfets-interrupts-using-tps48110-driver
Basically I making this post to share my expirience, because today i got the problem and I fixed it (or fixed it for a while until my use case will be changed)
About the main driver feature - inrush current limiting works great, i made it just with a datasheet info and recommendations, once I red a thread I also recalculated everything with Excel files were mentioned in a thread, everything match it, MosFET has ~2.1 margin to derated FET SoA.
However i got stuck with constantly blowingup FETs at random moment.
My setup is: bi-directional power supply (it is good and expensive PS, i chose bi-dir exactly to absorb any back-EMF etc.), Board with three output channels - one driver per each, one FET per channel IAUT300N10S5N015, then a robo-leg with three actuators. Maximum working voltage is 70V, working current is only up to 1 Amp per actuator.
My device also has an E-stop input, so at sturtup when voltage is applied to device it is turned off and all channels turned off. When i release E-stop all channels turns on.
Then after some tests with robo-leg when i tried to turn off outputs i got that some of them still on. Later i caught the moment when FET dies but it is very specific use case, won`t describe it here. And i was getting this situation many times. With an oscilloscope i got that obviously FET dies because of thermal overstress, not at start up while it limits inrush current but when FET is fully on - because driver unexpectedly turn it on/off in a short time ( i will also upload some pictures of that).
Cboost is stable, EN pin voltage also stable, and on INP pin where goes my E-stop i cought unexpected noise. I didn`t add any extra components to driver circuits but added it to E-stop circuit and it helped. I still have some i gues inductive spikes on gate-source pins (will add picture) but main problem solved.
So again, I first time in this forum, if my post doesn`t make sense, excuse me :) Also I would be very glad to anyone if you have any thought how to improve my schematic/fix that inductive spike on Gate-source :)
Have a nice day!
