30V rail clamp — the protection window
Its 30V reverse standoff voltage sits above the rail's steady-state tolerance, while the 33.3V minimum breakdown and 64.3V maximum clamp at 36A define the overvoltage window — the rail sees no conduction below 33.3V, and the clamp holds the transient below 64.3V even at the peak pulse current.
400W peak pulse — energy handling in the DO-214AC footprint
The 36A peak pulse current at the 8/20µs waveform gives a realistic surge rating for industrial and telecom transient events.
STMicroelectronics lists the SMAJ30A-TR as Active.