15V rail clamp, 500W pulse, bidirectional
Its 15V reverse standoff voltage matches 12V or 15V nominal rails, clamping at 26.9V max before the downstream circuitry sees overstress.
Junction temperature and power derating
The 500W rating is at 25°C; derate linearly above that per the datasheet curve — at 125°C ambient the effective pulse power drops to roughly 60% of the 25°C figure. The 18.8A peak pulse current at the 10/1000µs waveform gives the surge budget for a typical 24V system transient — but the 15V standoff means it triggers below the 24V rail, so it is not a primary clamp for a 24V bus. Use it on downstream 12V or 15V regulated rails.
Active production, DO-214AC footprint
Microchip continues to manufacture the part in the DO-214AC (SMA) package, supplied on Tape & Reel. The DO-214AC footprint is shared across the SMAJ family, so a BOM swap to a different voltage rating (e.g., SMAJ5.0 or SMAJ30) requires no board layout change — only the silkscreen marking.