What the 1500 W bidirectional rating means for circuit protection
The 1.5KE170CAHE3/51: This is the energy the diode can absorb in a single transient event before the junction exceeds its thermal limit. For a 145 V reverse standoff (working voltage), the clamp fires at 162 V minimum breakdown and holds the peak to 234 V maximum at the 6.4 A peak pulse current. Bidirectional construction (one device, single channel) means it clamps equally on positive and negative transients — no polarity marking needed on the axial leads. This suits AC-coupled signal lines or DC buses where the surge polarity is unknown.
Package, mounting, and board-fit details
Through-hole axial package (DO-201AA / DO-27) with the 1.5KE body size. The axial leads let it sit above the board for convection cooling or lie flat in a card-edge slot. Bulk packaging means loose tubes or bag — no tape-and-reel for automated pick-and-place. The 175°C max junction temp covers underhood engine-bay ambient plus self-heating during the pulse.