Hello.
I have made the scheme 12V to 1V converter on TPS40305 and two MOSFETs CSD17308Q3 using ti webench.
1V is used for FPGA powering.
Separately the board with FPGAs powered from 1V source works normally and the DC/DC source with 1V output works normally.
But I have problem when I connect it together. Upper MOSFET is going to be shorted and TPS40305 is damaged. I don't know who is firstly going to be damaged.
Today's experiments show that DC/DC source can fail even not connected to main board. It seams that it can depend on the quality of input 12V. Perhaps, when I connect by hands through terminals whith switched on source some noises can cause the fail. But I don't think that 12V on board is with noises because I use TPS2420 for hotswap.
Why is it going to be damaged?
Thank you in advance.