The 1.5SMC39AT3G: It clamps at 53.9V max with a 28A peak pulse current, protecting downstream circuitry from overvoltage transients on a 33.3V nominal rail. This is a unidirectional device (one channel) with a minimum breakdown voltage of 37.1V. It is not intended for power-line protection — the internal structure is optimized for signal and DC rail transients.
Littelfuse lists the 1.5SMC39AT3G as Obsolete. For existing BOM lines, this part is sourced through independent distribution channels — quantities are lot-specific and confirmed at RFQ. No stock-holding claim; availability and pricing are quoted per order.
Package and board-fit considerations
The DO-214AB (SMC) body measures about 7.1 mm long by 6.2 mm wide — a standard footprint for this power class. The cathode band marks polarity; rework with hot air is straightforward if the pad layout matches the recommended land pattern. The SMC package's larger body compared to SMA/SMB means it handles the 1500W pulse without exceeding the junction temperature limit in most layouts.