The 1.5SMCJ190A_R1_00001 is a unidirectional Zener-based TVS diode with a 190 V reverse standoff voltage — the maximum rail voltage it allows to appear across the protected node without conduction. When a transient exceeds the breakdown threshold, the device clamps the output to a defined let-through level, absorbing up to 1500 W peak pulse without damage.
What the clamping and breakdown specs mean in-circuit
Minimum breakdown is 209 V — once the transient crosses that threshold the TVS enters conduction and the clamping network takes over. A 4.8 A peak pulse current at 308 V clamping is consistent with the 1500 W peak pulse rating — those three numbers are linked by the same transient event.
The DO-214AB (SMC) package is the standard foot-print for this power class; land-pattern and solder-joint geometry are driven by the 1.5 kW transient rating and the thermal path from junction to PCB pad.