1.5kW surge protection for telecom and industrial DC rails
The Littelfuse 1.5SMB75CA is a 1500W bidirectional TVS diode in the DO-214AA (SMB) surface-mount package. It clamps transients on a 64.1V nominal DC rail — typical for telecom rectifiers, 48V battery-backed systems, and industrial control power supplies where a single bidirectional device replaces two unidirectional TVS diodes in series. The 133.1V clamping voltage ensures downstream DC-DC converters and ASICs stay within their absolute-maximum ratings during a surge event.
Breakdown and clamping thresholds
The reverse standoff voltage is 64.1V — the device draws negligible leakage below this level. This 2:1 clamping ratio is typical for Zener-type TVS diodes in this power class. Bidirectional configuration means the 1.5SMB75CA protects both positive and negative transients with a single component — useful on signal lines or power rails that swing relative to ground. The single channel covers both polarities, saving placement cost and PCB area compared to a back-to-back unipolar pair. Operating temperature spans -65°C to 150°C junction, covering military/aerospace cold-soak and under-hood automotive hot-spot conditions.
Active production — no EOL concerns
It is a current-production part available through authorized distribution and independent channels. No successor or cross-reference is needed; the part is the standard offering for this voltage and power class.