3 A Schottky in an SMC body — the footprint trade-off
The STPS3L40S is an STMicroelectronics Schottky rectifier rated 40 V reverse voltage and 3 A average rectified current, in the SMC package. The SMC footprint is larger than the SMA or SMB typically used for 3 A Schottkys, which gives the designer more copper area for heat sinking without needing a separate heatsink.
The recovery time is listed as ≤500 ns at >200 mA. For a Schottky diode the recovery is majority-carrier dominated, so the stored charge is minimal — the 500 ns ceiling is conservative. In a 100 kHz boost or flyback converter the reverse recovery loss is negligible, and the diode does not force a dead-time penalty.
The base product number STPS3 covers a family of 3 A Schottkys; the L40 variant is the 40 V grade in the SMC package.