The 1.5SMC120CAHE3/9AT: This part carries AEC-Q101 automotive qualification, so it's screened for the temperature and reliability demands of under-hood and chassis-mounted electronics — engine control units, transmission controllers, and body modules that see -65°C to 150°C junction temperature.
Peak pulse power and clamping — what the ratings mean for your BOM
The breakdown voltage range starts at 114 V minimum, ensuring the diode doesn't conduct during normal 102 V standoff operation.
Housed in the DO-214AB (SMC) package, also referred to as SMCJ, this is a surface-mount package with a standard footprint. The wide copper tab on the bottom side carries the heat to the PCB copper plane — the 1500 W rating assumes a good thermal connection to the board, so the layout should include a solid pad and thermal vias under the package.