I've been looking for a solution to provide solid-state overcurrent protection for automotive loads such as small water pumps (0.6A continuous), fans (3.5A continuous) and fuel pump (8A continuous).

Initially I looked into integrated high side switches such as the following: https://www.mouser.com/datasheet/2/389/vnd7004ay-973698.pdf

Recently, I found something from Texas Instruments which they call an E-Fuse. It performs essentially the same functionality as the high side MOSFET switch linked above, but integrates a lot more features like inrush current blanking, programmable current limitation with auto retry, high accuracy current sense at <15A etc. It does this all while having a lower Rds than the automotive switch.

Link: http://www.ti.com/lit/ds/symlink/tps25982.pdf

I have not been able to find an "automotive" high side switch with similar functionality (especially accurate current sense combined with low Rds). My question is, would there be an issue with using the TI part, which is intended for servers and computing applications, in a one-off automotive application?

  • \$\begingroup\$ What is the starting current for the fuel pump? \$\endgroup\$ – DKNguyen Sep 21 '19 at 19:12
  • \$\begingroup\$ @DKNguyen ~ 12A \$\endgroup\$ – user202237 Sep 21 '19 at 19:13
  • \$\begingroup\$ Seems like it'd be okay as long as you add the extra voltage clamping which the e-fuse is missing. \$\endgroup\$ – DKNguyen Sep 21 '19 at 19:17
  • \$\begingroup\$ Ok, a TVS on the input and a schottky across the load \$\endgroup\$ – user202237 Sep 21 '19 at 19:20
  • \$\begingroup\$ But have you actually calculated the operating temperature? \$\endgroup\$ – DKNguyen Sep 21 '19 at 19:20

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