30 mOhm Rds(on) — what it buys the load circuit
The Infineon BTS432E2BKSA1 is a single-channel PROFET high-side power switch rated for a continuous output current of 9 A with a typical on-resistance of 30 mOhm. That Rds(on) figure sets the conduction loss floor: at 9 A the I²R dissipation is about 2.4 W, which the TO-220-5 package (PG-TO220-5-3) must sink through the board or a heatsink tab.
Built-in fault protection saves board space
The BTS432E2BKSA1 integrates current limiting (fixed), open-load detection, over-temperature shutdown, and over-voltage clamping. For a design engineer, this means the switch handles most fault conditions autonomously — no external sense resistor, no comparator, no latching circuit. The auto-restart feature re-enables the output after a thermal fault once the junction cools, which is useful for driving lamps or motors where a temporary overload is expected.
Infineon lists the BTS432E2BKSA1 as obsolete. If the design can tolerate a footprint change, a current-production PROFET in a similar TO-220-5 package is the practical path; otherwise, stock up while the surplus channel still carries inventory.
Temperature grade and deployment context
The through-hole TO-220-5 package with formed leads allows the tab to be bolted to a heatsink or chassis ground — a common practice in motor-drive and solenoid-drive circuits where the 9 A output is used near its limit.