1500W bidirectional clamp for a 40.2V automotive rail
The 1.5SMC47CAHM3/H: It clamps a 40.2V reverse standoff rail to 64.8V maximum at 23.1A peak pulse current. Bidirectional single-channel construction — one device protects both polarities on a signal or power line, common in automotive and telecom applications where the line sees positive and negative transients.
Qualified to AEC-Q101, the automotive discrete semiconductor reliability standard.
Clamping voltage and peak pulse current — what they mean for a 40.2V rail
The 40.2V reverse standoff is the maximum DC or peak-AC voltage the TVS leaves untouched. Breakdown triggers at 44.7V minimum, clamping the transient at 64.8V maximum — that 24.6V clamp headroom ensures the downstream IC's abs-max rating (typically 1.3x the rail) is not exceeded on a 40.2V bus. For automotive load-dump pulses (ISO 7637-2 pulse 5a/5b), the energy is lower but the peak voltage is higher — the 1500W rating handles a 60V load-dump on a 40.2V rail with margin.
DO-214AB (SMC) surface-mount — board-fit note
The copper pad area under the cathode tab sets the thermal resistance — a 300mm² copper pour on a 2oz board keeps RthJA below 60°C/W for the 1500W pulse. Supplied on Tape & Reel (TR) for automated pick-and-place.