100 V / 1 A Schottky — the automotive under-hood rectifier
The STPS1H100AY is a 100 V, 1 A Schottky rectifier from STMicroelectronics' Q Automotive series. It is designed for high-temperature automotive environments, with a junction temperature rating of 175°C that exceeds the standard 150°C limit for Schottky diodes. The 770 mV forward voltage at 1 A keeps conduction losses manageable in a DO-214AC (SMA) surface-mount package.
175°C junction — the under-hood margin
Standard Schottky diodes typically top out at 150°C, so the extra 25°C headroom is what makes this part suitable for engine-bay or transmission-mounted rectification where ambient temperatures push past 125°C. The reverse leakage at 100 V is 4 µA at room temperature — expect that to rise with junction temperature, but the 175°C rating means the part is characterised for the full automotive temperature sweep.
Q Automotive series — AEC-Q101 compliance
The Q Automotive series designation means this diode is qualified to AEC-Q101, the automotive stress-test qualification for discrete semiconductors. That qualification covers extended temperature cycling, high-temperature reverse bias, and humidity testing — the standard for any part going into a safety- or emissions-related automotive ECU.