The Infineon BTS4142NHUMA1 is a single-channel high-side power switch in a PG-SOT223-4 package, built for switching 12V to 45V loads up to 1.4A. Its 150 mOhm typical on-resistance means at 1A you are dropping about 150 mV across the switch — figure that into the load voltage budget, especially if the supply rail is already near the 12V low end.
Fault protection set — what is built in and what still needs external parts
This switch integrates current limiting (fixed), over-temperature shutdown, and over-voltage clamping. That covers the common failure modes for an inductive or resistive load on an automotive or industrial rail. The Auto Restart feature means after a thermal fault clears, the switch tries to turn back on automatically — useful for a lamp or motor that might cool and recover, but something to be aware of if you want latched-off behaviour after a fault.
The PG-SOT223-4 package has a thermal pad — in a layout, stitch vias to a copper plane on the bottom layer to keep the junction temperature down at the 1.4A max. No external Vcc supply is required; the switch is self-powered from the load rail.
Active, ROHS3, and the sourcing picture
Marked as Active in the lifecycle status and ROHS3 compliant, so no end-of-life pressure for current or new designs. The base product number is BTS4142, which helps when searching for related variants in the family.