Package and board-fit
The SMCJ78A-13-F: The DO-214AB (SMC) package is a standard surface-mount footprint with a large copper pad on the cathode side to conduct heat into the PCB. The -55°C to 150°C junction temperature range covers industrial and military-grade environments — a 78 V bus in a telecom rectifier or an avionics 28 V rail doubled by a boost stage both fall inside the operating envelope. The single unidirectional channel means polarity matters: the cathode band must face the protected rail, anode to ground.