Forward voltage and conduction loss at 2 A
The STPS2L40U is a Schottky rectifier rated for 2 A average forward current with a maximum forward voltage of 430 mV at that current. That 430 mV drop at 2 A means the conduction loss is under 1 W — the SMB package can dissipate that without exceeding the 150°C junction limit, assuming reasonable board copper and ambient below 85°C. Reverse leakage is specified at 220 µA when the device is blocking 40 V. For a 2 A diode this leakage is typical for a low-Vf Schottky — the trade-off for the low forward drop is higher reverse current at temperature, so the junction temperature budget needs to account for self-heating from leakage at high ambient.
Package and board integration
The SMB footprint is a common industry standard — the same pad layout serves many 2 A Schottky diodes, so a board designed for this part can accept a second-source alternative without a layout change.