The 1.5SMC33A TR13 PBFREE is a 1500W Zener TVS diode from Central Semiconductor Corp, packaged in a DO-214AB (SMC) surface-mount body. It is designed to clamp transient overvoltage events on a DC rail up to 28.2V normal operating voltage. For a 24V nominal bus, the 28.2V reverse standoff leaves margin above the rail before the TVS starts conducting leakage.
Breakdown and clamping window
Breakdown voltage is guaranteed at 31.4V minimum, with the clamp limiting the transient to 45.7V maximum at the rated 33A pulse. This window means a 24V rail sees the TVS as an open circuit until the surge pushes the line above 31.4V, then the clamp holds the peak below 45.7V — well within the typical 60V abs-max of downstream DC-DC converters. Unidirectional (single channel) construction — the cathode band marks the protected side; the anode connects to ground. For a positive DC rail, that is the correct polarity.
Surface-mount assembly and sourcing
Supplied in Tape & Reel (TR) for automated pick-and-place.