The Infineon BTS409L1E3062ANTMA1 is a PROFET single-channel high-side power switch rated for load voltages from 5 V to 34 V and a continuous output current of 1.8 A maximum. The switch integrates a full set of fault protections: current limiting (fixed), open-load detection, over-temperature shutdown, over-voltage clamp, and under-voltage lockout. These cover the common failure modes in a switched-load channel without external supervisory components.
160 mOhm Rds(on) and 1.8 A output — thermal budget
The 160 mOhm typical Rds(on) is the value at 25 °C junction; expect the on-resistance to rise with temperature per the normalised curve in the datasheet. For a 1.8 A continuous load, the I²R conduction loss at 25 °C is about 0.52 W. In the TO-263-5 (D²Pak) package, the copper area on the drain tab sets the junction-to-ambient thermal resistance — a 1 in² pad keeps the junction rise within the -40°C to 150°C operating range for most ambient conditions.