What the 1500W peak pulse rating means on your board
The 1.5SMC160CAHM3/H is a 1500W (1.5kW) bidirectional TVS diode from Vishay's automotive-grade 1.5SMC series, built to clamp transients on 136V rails. The 1500W rating is peak pulse power for a 10/1000µs waveform — that's the energy it absorbs in a single surge event, not continuous dissipation. On a 136V nominal bus, a spike that would otherwise punch through downstream silicon gets clamped at 219V max, shunting 6.8A peak pulse current through the die.
Voltage thresholds that define the protection window
Three voltage numbers set the operating boundaries: reverse standoff at 136V (the DC bus voltage it blocks without conducting), breakdown at 152V minimum (where it starts to avalanche), and clamping at 219V max at the rated 6.8A peak pulse current. The gap between 152V and 219V is the clamping region — the lower it is, the tighter the protection. For a 136V rail, this part keeps the transient ceiling under 220V, which is safe for most 150V-rated downstream components.
DO-214AB (SMC) package and board integration
The bidirectional configuration means a single device protects both polarities on the line — no need to pair two unidirectional diodes back-to-back. The package footprint is standard for the 1.5SMC series, so a board layout for the base number 1.5SMC160 accepts this variant without changes.