Automotive-grade TVS for 48V rail clamping
The 1.5SMC56CAHE3/9AT: It clamps a 47.8V nominal rail to 77V maximum, with a breakdown voltage starting at 53.2V. This is the part you reach for when a 48V automotive bus — think mild-hybrid or EV auxiliary supply — needs transient protection that doesn't fail open after one load-dump event.
AEC-Q101 and the 1500W pulse
AEC-Q101 qualification means this diode passed the automotive stress suite: temperature cycling, high-temperature reverse bias, and ESD robustness. The 1500W pulse rating is tested with a 10/1000µs waveform — a standard for automotive transients like ISO 7637-2 pulses. The bidirectional configuration (one channel) clamps both polarities, so you don't need two diodes in anti-series on a symmetrical rail. At 150°C the leakage current rises, but the diode still holds its clamping voltage within spec — the TransZorb® die design handles the thermal stress without secondary breakdown.
DO-214AB footprint and board integration
The supplier device package is listed as DO-214AB (SMCJ), which is the same body size. The cathode band on the package marks the polarity for the unidirectional variant; on this bidirectional part, the band is still present but the device clamps both ways. The pad layout should follow the JEDEC standard for SMC — the copper area under the tab sets the thermal impedance for the 1500W pulse.