The SMAJ45CA-13 is a 400W peak pulse power TVS diode in a bidirectional Zener configuration — rated for a 45V reverse standoff voltage, meaning it stays transparent on a 45V rail and only starts conducting when the transient exceeds the 50V minimum breakdown threshold. Clamping is specified at 72.7V maximum at the 5.5A peak pulse current (10/1000µs waveform), so a 45V bus sees the surge clipped to under 73V before the TVS absorbs the energy — the 400W rating is the product of the clamp voltage and the peak current under that waveform.
Package and board-fit for automated assembly
Housed in the standard DO-214AC (SMA) surface-mount package with a supplier device package designation of SMA — the footprint matches the common SMA pad layout used across the industry, so no board respin is needed if replacing an existing SMA TVS.