45 V, 15 A Schottky — where it fits and what it costs thermally
The STPS1545R is a 45 V, 15 A Schottky rectifier from STMicroelectronics in a through-hole TO-262 (I2PAK) package. The 45 V reverse voltage rating gives comfortable margin on a 24 V DC bus or a 12 V automotive rail, but it won't hold up on a 48 V telecom supply — that's the first fit check. The 15 A average rectified current is the continuous load number; for a 10 A output power supply this diode runs with reasonable junction temperature, but at full 15 A you need to size the heatsink for the conduction loss. Forward drop is specified at 840 mV at 30 A, which is twice the average rating — that's the surge or startup condition. At the nominal 15 A the Vf will be lower, but the 30 A point is what you use for worst-case thermal budgeting in a short-duration overload. The Schottky construction gives fast recovery with negligible reverse-recovery charge, so switching losses stay low in a 100 kHz PFC or output rectifier stage.
STMicroelectronics lists the STPS1545R as obsolete. That means no new factory orders, no last-time-buy window — the only channel is independent distribution or surplus stock. If you have this on a BOM for a production board, you need to qualify a replacement or secure a lifetime buy from the spot market. The base product number is STPS1545, and ST may still offer a similar active Schottky in the same I2PAK package — check the STPS1545 family for a current-production variant with the same 45 V, 15 A ratings.
Through-hole I2PAK — mounting and thermal interface
The supplier device package is I2PAK. Unlike a surface-mount D²PAK, this one goes through the board and can be bolted to a chassis or heatsink — useful for designs where the PCB copper alone can't sink 15 A of continuous current.