Zener TVS for 36.8 V rail protection
The 1.5SMC43AT3 is a single-channel unidirectional Zener TVS diode from onsemi, designed to clamp transients on a 36.8 V nominal rail (reverse standoff voltage) to a maximum of 59.3 V at the peak pulse current of 25.3 A (10/1000 µs waveform). Rated for 1500 W peak pulse power, it absorbs surge energy in a surface-mount package, suitable for general-purpose overvoltage protection on DC power buses, signal lines, and I/O ports.
Clamping voltage and breakdown margin
The minimum breakdown voltage is 40.9 V. The clamping voltage at 25.3 A is 59.3 V. Operating temperature range spans -65°C to 150°C junction, covering automotive under-hood and industrial outdoor enclosures without derating concerns at the cold end.
Obsolete — sourcing and replacement planning
onsemi has marked the 1.5SMC43AT3 as Obsolete. No official successor is listed in the available records. For a BOM line that must stay active, a parametric cross-search within the 1.5SMC series for a 36.8 V standoff Zener TVS is the first step. Sourced and quoted per RFQ against the BOM quantity.