A high-side switch that handles the rough stuff
The Infineon BTS4140NNT is a single-channel high-side power switch in a PG-SOT223-4 package, designed to drive resistive, inductive, and capacitive loads from a 4.9V to 60V supply rail. It delivers up to 200 mA continuous output with a typical on-resistance of 1 Ohm, keeping voltage drop and self-heating manageable even in a tight layout. The switch integrates current limiting, over-temperature protection, and over-voltage clamping — so a shorted load or a load-dump transient won't take out the trace or the MCU GPIO driving it.
The 60 V load voltage ceiling means this switch sits comfortably on 12 V and 24 V vehicle electrical systems, and it has headroom for 48 V industrial bus rails. The 200 mA continuous output is enough for relays, solenoids, indicator LEDs, and small DC motors — but not for a headlamp or a pump. The 1 Ohm Rds(on) at 200 mA drops only 0.2 V, so the load sees nearly the full rail voltage. The auto-restart feature (listed in the features) means the switch tries to re-energise the load after a fault clears — useful for a lamp that cools down or a motor that un-stalls, but something to note if you want latched-off behaviour.
Lifecycle reality — obsolete, but sourced
The BTS4140NNT carries an obsolete lifecycle status. Infineon no longer manufactures it in volume, and there is no official successor listed on the record.
Package and footprint for the board
The PG-SOT223-4 package (TO-261-4 equivalent) is a surface-mount footprint with a large tab for thermal dissipation. The 1:1 input-to-output ratio means one GPIO pin controls one load — no serial interface, no diagnostics, just On/Off via a non-inverting input.