The SMAJ33AE3/TR13: This is a current-production part you can order against a BOM line without planning a substitution.
33V rail clamp with 500W surge capacity
This is a Zener-type TVS diode designed to protect a single 33V DC rail. The reverse standoff voltage is 33V — the diode stays off below that level and starts conducting when the rail exceeds the minimum breakdown voltage of 36.7V. The 500W peak pulse power rating tells you how much transient energy the diode can absorb in a 10/1000µs waveform before failing.
One channel, unidirectional, no power-line protection
The SMAJ33AE3/TR13 is a unidirectional device with one channel. It clamps only one polarity — the cathode is tied to the protected rail, the anode to ground.
DO-214AC (SMA) – surface-mount footprint
The package is DO-214AC, also called SMA. It is a standard surface-mount footprint with two terminals. The Tape & Reel (TR) packaging means the parts come on a reel.
Wide temperature range suits industrial environments
The 150°C upper limit also gives headroom for self-heating during repetitive surge events.