What the 1500W rating buys you in a 17V rail
The 1.5SMBJ17A-H: On a 17V nominal rail (the reverse standoff voltage), it stays off until the transient pushes past 18.9V breakdown, then clamps at 27.6V maximum while shunting 54.4A peak pulse current. The 10/1000µs pulse is the telecom/industrial standard; a shorter automotive pulse (8/20µs) lets it handle a higher peak current, but the 1500W rating is the safe comparison across datasheets. The -55°C to 150°C junction range covers under-hood ambient and self-heating during repetitive surge events — no derating worry at 85°C ambient as long as the average power stays within the thermal impedance of the DO-214AA pad.
DO-214AA (SMB) is a standard surface-mount footprint shared across Bourns, Littelfuse, and STMicro TVS diodes in the same power class. The cathode band is marked on the body; the unidirectional orientation is obvious under a magnifier. Reflow profile follows JEDEC J-STD-020 for a moisture sensitivity level 1 part — no bake required before assembly if the reel seal is intact.