Clamping voltage and the rail it protects
The 1.5SMC350AHE3_A/H: The margin between the operating rail and the clamp voltage determines how much overvoltage the downstream silicon sees before the TVS turns on hard.
Automotive qualification and temperature envelope
This diode carries AEC-Q101 qualification, meaning it has passed automotive-grade reliability stress tests including high-temperature reverse bias, temperature cycling, and ESD robustness per the AEC-Q101 discrete semiconductor standard. The single unidirectional channel means it protects one polarity — the cathode band orients toward the positive rail being clamped.
Package and board-fit decision
The tape-and-reel packaging suits automated pick-and-place assembly.
Sourcing an obsolete AEC-Q101 TVS
Vishay has marked the 1.5SMC350AHE3_A/H as obsolete. For new designs, a 300V standoff, 1500W peak-pulse, AEC-Q101 qualified TVS in a DO-214AB package from the same or an alternate manufacturer should be evaluated for functional equivalence — a board layout change is not required if the footprint and pinout match, but the breakdown and clamp voltage tolerances must be verified against the rail being protected.