The BTS555 is listed as obsolete by Infineon. Existing BOM lines that call out this part must be sourced through the surplus or broker channel — there is no official last-time-buy window remaining.
1.9 mOhm Rds(on) — the headline rating
The BTS555 is a single-channel high-side N-channel power switch from Infineon's PROFET series. Its headline spec is a typical on-resistance of 1.9 mOhm, which is extremely low — this part is designed to switch very high currents with minimal conduction loss. The maximum continuous output current is rated at 128 A, though in practice the thermal capability of the TO-218-5 package will limit sustained current well below that figure, especially at elevated ambient temperatures.
Voltage range and protection features
The load voltage range spans 5 V to 34 V, covering common automotive and industrial supply rails. The switch includes a full suite of fault protections: current limiting (fixed), open-load detection, over-temperature shutdown, and over-voltage clamping. These built-in protections reduce external component count and simplify the design of rugged power distribution systems.
Package and temperature grade
The BTS555 comes in a TO-218-5 through-hole package (supplier device package TO-218AB/5). The through-hole package is field-serviceable — a technician with a soldering iron can swap it on site without hot air.