What the 1500 W peak pulse rating means for your protection design
The 1.5KE120-E3/73: The 8.7 A peak pulse current (10/1000 µs waveform) and 173 V maximum clamping voltage define the protection window: the diode begins conducting at the 108 V minimum breakdown voltage and limits the voltage across the protected circuit to 173 V at the rated surge current.
Through-hole DO-201AA package and board integration
Housed in a DO-201AA (DO-27) axial-lead through-hole package, the 1.5KE120-/73 mounts directly into a PCB or terminal strip.
Obsolete — sourcing through independent channels
Vishay has marked the 1.5KE120-/73 as obsolete. No pin-compatible direct replacement from Vishay is documented; a parametric search on 1500 W, 97.2 V standoff, and DO-201AA package will identify functionally similar TVS diodes from other manufacturers if a board spin is acceptable.