1500W peak pulse — the clamping envelope for 214V rails
The 1.5SMC250A-M3/9AT: It protects a 214V nominal rail — the reverse standoff voltage — and clamps transients at 344V maximum before the 4.4A peak pulse current is reached. The 1500W rating means it absorbs a 1 ms surge without failing open or short — the energy is dissipated across the die and into the DO-214AB package's copper pad. For a 250V-rated bus, the 237V minimum breakdown voltage ensures the device triggers before the downstream silicon sees overvoltage.
DO-214AB footprint and thermal path
Tape & Reel packaging (the /9AT suffix) feeds pick-and-place at 8 mm pitch on 13-inch reels. The moisture sensitivity level (MSL) is typically Level 1 for this glass-passivated die, so no bake-out is needed before reflow.
The base product number 1.5SMC250 covers the full family; the -M3/9AT suffix denotes the specific packaging and reel configuration. No pin-compatible second source is documented in the ledger, but the 1.5SMC series is a standard JEDEC outline, so parametric equivalents from other vendors exist at the same DO-214AB footprint.