The STPS30L40CW is a dual Schottky rectifier from STMicroelectronics, with two diodes in a common-cathode configuration inside a single TO-247-3 through-hole package. Each diode is rated for 15 A average rectified current and a maximum reverse voltage of 40 V, with a forward voltage drop of 550 mV at 15 A — the conduction loss at full load is about 8.25 W per diode, so the total heat to manage is roughly 16.5 W if both diodes are conducting at rated current. The fast-recovery characteristic (≤ 500 ns, > 200 mA) makes it suitable for switching power supplies and output rectification where Schottky's low Vf and fast turn-off reduce losses compared to a standard pn-junction diode.
Obsolete — plan your BOM move now
The STPS30L40CW is listed as obsolete. Any new design should not specify this part; existing BOM lines need a qualified replacement or a last-time-buy inventory bridge. The closest functional alternative is the STPS30L40C (without the 'W' suffix), which shares the same base product number and common-cathode TO-247-3 package — but the 'W' suffix may indicate a specific lead-free or packaging variant, so verify pin compatibility and electrical ratings before substituting.
Package and thermal reality — TO-247-3 through-hole
The common-cathode configuration means the two cathodes are internally tied to the tab, so the tab is live at the cathode potential — electrical isolation from the heatsink is required unless the system ground matches the cathode voltage. With 360 µA reverse leakage at 40 V, leakage-induced heating is negligible at room temperature but rises with junction temperature — budget for it in high-temperature environments.