30 mOhm Rds(on) — what it buys the load circuit
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
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.
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.