Protection parametrics and clamp performance
The 1.5KE39A-E3/54: Its 33.3 V reverse standoff voltage means the protected rail can run at 33 V DC without the diode conducting leakage; the breakdown voltage range starts at 37.1 V, and clamping is specified at 53.9 V maximum when the peak pulse current reaches 27.8 A. The 53.9 V clamp voltage is the hard limit the downstream circuitry must survive — if your 36 V bus sees a transient, the diode holds it under 54 V, which is well within the 60 V abs-max of many downstream DC-DC converters and linear regulators.
Package and board integration
Housed in a DO-201AA (DO-27) axial-lead package, the 1.5KE39A-/54 is a through-hole part — it stands off the board and can be hand-soldered or wave-soldered. The axial body is common for TVS diodes in this power class, and the lead spacing fits standard 0.3-inch pitch holes. The wide range means the diode's leakage and breakdown voltage drift remain within spec across the full temperature swing.
Lifecycle and supply posture
The base product number is 1.5KE39, and the suffix -/54 indicates the lead-free, RoHS-compliant version in tape-and-reel packaging. Cut tape options are also listed.