Mahmood,

The only people still using 1553 are legacy military avionics types.

re: chipset. You'll probably find it easiest to buy an expensive chip from DDC, even though the protocol is fairly simple and slow and can be done in a small FPGA. The reason? The DDC parts are qualified and if that's a customer requirement, you've got no choice.

re: the transformer. It's not about short circuit protection; it's more for isolation.

Good luck.

-a