1.5SMB33A — 1500 W Zener TVS for Telecom Protection
The 28.2 V reverse standoff voltage means the diode stays transparent on a 24 V rail, only conducting when the line exceeds the breakdown threshold.
Clamping and Thermal Performance
For a 24 V rail, the 31 V margin between standoff and clamp gives the downstream regulator or IC enough headroom to survive without secondary protection. Operating temperature spans -65°C to 150°C junction, covering outdoor telecom cabinets and unheated enclosures. The DO-214AA (SMB) surface-mount package dissipates the 1500 W pulse through the PCB copper — the thermal path is through the solder joint to the board plane, not the plastic body.