100 V Schottky for 48 V and 12 V automotive rails
The STPS3H100UFY is an STMicroelectronics automotive Schottky rectifier rated at 100 V reverse voltage and 3 A average forward current, in the low-profile SMBflat (DO-221AA) surface-mount package. The 100 V VR rating provides the derating margin needed for 48 V mild-hybrid bus rails and for reverse-battery protection on 12 V systems where load-dump transients can exceed 40 V. AEC-Q101 qualification means this part meets the automotive stress tests for production-vehicle use — thermal cycling, HTRB, and humidity bias are already characterised.
3 A in SMBflat — thermal budget matters
At 3 A average rectified current the SMBflat package relies on the PCB copper area for heat spreading; the junction-to-ambient thermal resistance is set by the layout, not the device alone. Forward voltage is specified at 940 mV maximum at 6 A — this is a pulsed condition; the continuous conduction loss at 3 A will be lower, but the 940 mV ceiling bounds the worst-case efficiency for the alternator or DC-DC output OR-ing diode.
For a production automotive BOM this means the part is still factory-supported and can be quoted for multi-year programmes without the obsolescence contingency that NRND or EOL parts carry.