1500W surge clamp for 12V automotive rails
The 1.5SMC12A_R1_00001 is a 1500W peak-pulse-power Zener TVS diode from Panjit's 1.5SMC series, designed to clamp transients on 12V nominal supply lines. With a 10.2V reverse standoff voltage, it stays transparent during normal operation and begins conducting at 11.4V minimum breakdown, clamping the surge to 16.7V maximum at the 90A peak pulse current (10/1000µs waveform). That 16.7V ceiling is the key number for downstream component selection — anything on the protected rail must survive at least that voltage during the pulse. Rated for the -55°C to 150°C junction temperature range, this part is specified for automotive environments where the ambient under-hood temperature can push well above 85°C. The 1500W rating is the peak pulse power at 25°C; derate linearly above that per the datasheet curve, and the effective power handling drops to about 60% at 125°C junction.
Housed in the DO-214AB (SMC) surface-mount package, the same footprint as standard SMC diodes. The cathode band identifies the unidirectional polarity — reverse insertion defeats the protection. Available in Tape & Reel (TR) or Cut Tape (CT) for pick-and-place assembly; the reel quantity is the standard 3000 pieces per 13-inch reel for this package size. The mounting pad layout should follow the recommended SMC footprint in the Panjit application note: a copper pad area of at least 40 mm² on each terminal helps conduct the pulse heat into the PCB. The junction-to-ambient thermal resistance is dominated by the PCB copper area, not the package itself.