Protection window and surge rating
The 1.5SMB39A is a Zener-type TVS diode from the 1.5SMB series, designed to clamp transients on telecom signal and DC power rails. Its reverse standoff voltage is 33.3V — the rail voltage it sits across without conducting. Breakdown occurs at 37.1V min, and the clamping voltage at peak pulse current is 69.6V max, defining the protection window for the downstream circuitry. The single unidirectional channel protects one DC rail per package.
Package and board integration
Operating temperature range spans -65°C to 150°C, covering outdoor telecom cabinets and central-office environments. The part does not include power line protection — it is intended for signal or low-voltage DC rail clamping, not mains surge suppression.