What the 1500W rating means for your protection design
The 1.5KE440H: The clamping voltage hits 631V max at 2.4A peak pulse current — this sets the voltage the downstream circuitry must survive during a transient event. The 356V reverse standoff is the maximum DC voltage the diode blocks without conducting; for a 400V bus or a 277VAC line, this provides margin. Unidirectional configuration means it clamps only one polarity — suitable for DC rails where the transient is positive relative to ground. No power-line protection means it is designed for signal or DC bus clamping, not AC mains surge suppression.
Package and board integration
DO-201AA / DO-27 axial leaded package, supplier device package DO-201. Through-hole mount — the leads are 0.042-inch diameter, spaced 0.375-inch apart. The axial body sits above the board; no thermal pad or exposed paddle to consider. Tape-and-reel packaging is for automated insertion, not hand placement.