120 V rail surge clamp in a single SMA package
With a peak pulse power rating of 500 W (10/1000 µs waveform), it handles surge events up to 2.3 A peak pulse current before the clamp voltage reaches 214 V. The single bidirectional channel protects against both positive and negative overvoltage events, eliminating the need for two unidirectional devices and simplifying the PCB layout.
Standoff, breakdown, and clamp — the protection window
The minimum breakdown voltage is 133 V, so the diode starts clamping just above the normal operating range. At the full 2.3 A peak pulse current, the clamp voltage is 214 V max, which defines the voltage stress the downstream components must survive. This 94 V window between standoff and clamp gives a comfortable margin for a 120 V bus with typical ±10 % tolerance, but the clamp voltage is high enough that the protected circuitry should be rated for at least 250 V transient withstand.
DO-214AC footprint and reflow considerations
Housed in the DO-214AC (SMA) package, this diode is a surface-mount device compatible with standard reflow soldering profiles. The SMA footprint is common across many TVS families, so PCB layout reuse across different voltage ratings in the SMAJ series is straightforward. The wide temperature margin means derating for ambient heat is minimal in most applications, but the 500 W peak pulse rating is specified at 25°C — derate per the datasheet curve above that.