The SMCJ18E3/TR13 is a unidirectional Zener TVS diode from Microchip Technology, rated for 1500W peak pulse power (10/1000µs waveform) with an 18V reverse standoff voltage. It clamps transients to 32.2V maximum at 46.6A peak pulse current, making it a fit for 12V and 15V DC rails in industrial control, telecom, and general-purpose power supplies where a single surge event must not exceed the clamp ceiling.
With a 32.2V clamping voltage at 46.6A, this device keeps the protected bus below the absolute maximum rating of most 24V-tolerant ICs. The 20V minimum breakdown ensures the TVS triggers before the rail reaches damaging levels. The 1500W peak pulse rating covers common industrial surge requirements such as IEC 61000-4-5 Level 2 (1 kV/42 Ohm) when placed after a series resistor or fuse.