33V rail clamp — what the ratings tell you
The SMAJ33A-13 is a unidirectional TVS Zener diode from Diodes Incorporated, clamping a 33V nominal rail at 53.3V when hit with a 7.5A peak pulse (10/1000µs waveform). Rated for 400W peak pulse power, it shunts transients on a 33V supply line — think 24V industrial bus, 28V avionics, or 36V battery outputs — without the part self-destructing on a single event.
Breakdown window and clamping ceiling
Breakdown triggers at 36.7V minimum, so a 33V rail sitting at 10% tolerance (36.3V) stays below the avalanche knee — the diode only conducts when a real surge pushes past the regulation band. Clamp voltage of 53.3V at 7.5A peak pulse means downstream 40V-rated FETs or 50V-rated caps see a hard ceiling — the TVS absorbs the energy before the silicon behind it fails. No power-line protection — this is a signal-rail or low-side TVS, not meant for AC mains or high-energy industrial bus clamping where a higher joule rating is needed.
DO-214AC footprint and temp range
Packaged in DO-214AC (SMA), the same footprint as standard SMB/SMC TVS diodes — a rework tech can swap it with a hot-air station at 260°C peak profile without pad lifting. Operates from -55°C to 150°C junction — cold-crank battery dips at -40°C or engine-bay soak at 125°C both sit inside the safe operating area. Available on tape-and-reel or cut tape — pick-and-place ready for 8mm carrier pitch, 180mm reel for high-volume lines.
Status is Active — no EOL notice, no last-time-buy window. Diodes Inc continues to fab and assemble this part.