150 V, 1 A Schottky in a DO-41 axial — the power-stage clamp diode
The STPS1150RL is a 150 V, 1 A Schottky rectifier from STMicroelectronics in the through-hole DO-41 axial package. It is designed for low-voltage power-supply output rectification, freewheeling diodes in DC-DC converters, and reverse-polarity protection where the 150 V blocking voltage gives headroom above a 48 V or 72 V bus.
Forward drop and leakage — the thermal budget drivers
At 1 A forward current the maximum forward voltage is 820 mV — this sets the conduction loss at 820 mW at rated load. The reverse leakage is specified at 1 µA at 150 V, which keeps off-state dissipation negligible at room temperature, but Schottky leakage doubles roughly every 10°C rise, so at 125°C junction the leakage current can dominate the thermal budget if the heatsinking is marginal.
175°C junction — high-temp margin for cramped enclosures
The maximum junction temperature is 175°C, which gives a wider safety margin than the common 150°C Schottky limit. This matters when the diode is mounted in a sealed power supply or motor-drive enclosure where ambient air temperature inside the box can reach 85°C or more. The 175°C rating means the derating curve starts higher, so the same heatsink can carry more current at elevated ambient.
DO-41 axial — through-hole rework and board fit
The DO-41 (DO-204AL) axial-lead package is a through-hole legacy format. It is easy to hand-solder, inspect, and rework — useful for prototype builds, low-volume production, or repair scenarios where an SMD diode would need hot-air rework. The trade-off is board area: the axial body and formed leads take more PCB real estate than an SMB or SMA SMD package.
No official second-source or cross-reference is listed in the STMicroelectronics documentation, but the 150 V, 1 A Schottky in DO-41 is a common specification — any equivalent would need to match the 150 V blocking voltage, 1 A average current, and DO-41 footprint.