Clamping envelope and transient protection
The 1.5SMC43A-M3/9AT: Rated for 1500 W peak pulse power at 10/1000 µs waveform — this is the standard telecom surge shape, so the diode handles the full energy of a lightning-induced transient on a 36.8 V rail without the clamping voltage exceeding 59.3 V. The 25.3 A peak pulse current at the 59.3 V clamp means the diode can absorb a fault current limited only by the source impedance; a lower-impedance rail needs a series resistor or fuse ahead of the TVS to keep the pulse current within the rated envelope.
Breakdown window and standoff margin
Minimum breakdown voltage is 40.9 V, with a reverse standoff of 36.8 V — the rail sits 4.1 V below the avalanche threshold, so a steady-state 36.8 V supply sees no leakage until a transient pushes the diode into breakdown.
DO-214AB (SMC) body, also marked as SMCJ — the footprint is the same as the industry-standard SMC package, so a single pad layout covers both the Vishay and competitor parts in this power class. Supplied in Tape & Reel — the carrier tape pitch and reel diameter follow EIA-481, so it feeds through any standard pick-and-place without feeder changeover.
General-purpose application rating means no automotive or military screening; for high-reliability programs, confirm the specific Vishay qualification level (AEC-Q101 not listed on this variant).