The STMicroelectronics STPS3150AFN is a 150 V, 3 A Schottky rectifier in the low-profile SMA Flat Leads package. With a forward voltage of 820 mV at the full 3 A rated current and a fast recovery time under 500 ns, it is designed for high-frequency switching applications like secondary-side rectification in flyback converters, boost diodes in PFC stages, and freewheeling diodes in motor drives.
STMicroelectronics has discontinued production, so it is no longer available through the factory channel in new-manufacture quantities. For existing designs that already use the STPS3150AFN, the only sourcing path is the independent distribution market — surplus stock, new-old-stock, or broker-sourced material.
Ratings that decide the fit
The 150 V reverse voltage rating and 3 A average rectified current set the operating window. The 820 mV forward drop at 3 A is typical for a 150 V Schottky at this current. The fast recovery spec of <500 ns at >200 mA confirms it is a switching diode. The 175°C junction temperature means it can sit in a hot enclosure without derating prematurely.
The SMA Flat Leads package is a surface-mount, flat-lead variant of the standard SMA. The leads are coplanar and flush with the body, which reduces the mounted height compared to a gull-wing SMA — useful for low-profile board stacks.