1500W TransZorb — what the ratings mean for the automotive bus
The 1.5KE170AHE3_A/C is a unidirectional TransZorb TVS diode from Vishay's automotive-grade series, qualified to AEC-Q101. Despite the 'Zener' type label in the Circuit Protection category, this is a transient-voltage suppressor — it clamps overvoltage spikes, not regulates a DC rail. The 145V reverse standoff voltage means the diode stays off at normal bus levels; the 162V minimum breakdown is where conduction starts. Rated 1500W peak pulse power, the 1.5kW capacity absorbs the energy from a typical alternator load-dump or inductive kickback without the part failing short. The 175°C maximum junction temperature gives margin over the standard 150°C automotive limit, suiting under-hood or exhaust-adjacent placement where ambient heat is high.
Package and board-fit — DO-201AA axial
Through-hole DO-201AA / DO-27 axial package. The lead form is a legacy footprint but still standard in power distribution boxes and junction boxes where board space is not the constraint. The axial body handles the thermal pulse of a 1.5kW surge without delaminating the junction.