The 1.5KE150HE3/54: Breakdown occurs at a minimum of 136 V, giving a 15 V guard band above the standoff level before the device starts conducting. The single unidirectional channel protects a single rail or signal line.
The DO-201AA axial package (also known as DO-27) is through-hole mounted, suited for point-of-use protection on power inputs or high-reliability boards where a soldered lead provides mechanical strain relief.
Vishay lists the 1.5KE150HE3/54 as obsolete.
