TVS diode for 100V rail protection
The 1.5KE120-E3/54: Its 97.2V reverse standoff voltage and 108V minimum breakdown voltage mean it sits across a nominal 100V DC rail, clamping transients at 173V before they reach the downstream silicon. This is a unidirectional part — one channel, cathode band on the DO-201AA axial body. The through-hole package suits point-to-point wiring or PCB mounting where the lead bend absorbs thermal cycling strain.
What the ratings mean for your protection design
The 1500W peak pulse rating is the device's energy-handling capacity under the standard 10/1000µs test pulse. At the clamping voltage of 173V, the peak pulse current is 8.7A — the diode shunts that current to ground, holding the rail below the 173V ceiling. The wide range suits outdoor telecom or industrial enclosures where ambient heat plus self-heating from repetitive surges could push a narrower-grade part out of its safe operating area. The 97.2V standoff means it stays transparent below that voltage; leakage current is negligible until the transient pushes the rail above the breakdown threshold.
Obsolete — sourcing through independent channels
Vishay lists the 1.5KE120-/54 as obsolete. For a BOM line already qualified to this TVS, the DO-201AA axial footprint and 1500W pulse rating are the fit parameters. If a board spin is acceptable, a functional equivalent in the same package class may be cross-referenced at quote time.