What this TVS diode does on the board
The 1.5KE120AHE3_A/D is a unidirectional TransZorb® TVS diode from Vishay's automotive-grade series, clamping transients at 165 V maximum when hit with a 9.1 A peak pulse (10/1000 µs waveform). The 175 °C maximum junction temperature gives headroom under the hood on a hot day.
Automotive qualification and temperature reach
AEC-Q101 qualification means this diode passed the full automotive stress battery — high-temperature reverse bias, temperature cycling, and ESD robustness — so it belongs in an engine-bay ECU or a transmission controller without a second thought. Through-hole DO-201AA (DO-27 axial) package makes it a hand-solderable choice for prototype runs or rework, and the axial leads fit standard PCB hole patterns.
Sourcing and compliance reality
The base product number is 1.5KE120, so the same die and package are shared across the 1.5KE family. No pin-compatible second-source is listed, but the TransZorb® series is a standard footprint — any DO-201AA TVS with matching standoff and clamping voltage will fit the same board holes.