What the clamping voltage means for your rail
The 1.5SMB36A: The 30.8 V reverse standoff (working voltage) means the diode draws negligible leakage below that level — your 24 V supply rail stays clean during normal operation. That ceiling protects downstream DC-DC converters and line drivers rated for 65 V or higher. Operating temperature spans -65°C to 150°C junction, so it survives outdoor telecom cabinets and industrial enclosures without derating concerns at the board level. Power line protection is not built in — this is a signal- or low-power-rail protector, not a mains-side suppressor.
The supplier device package is DO-214AA (SMBJ), so the pad layout matches common SMB TVS diodes.