Surge protection envelope for a 28 V rail
The 1.5KE33CABULK: Its 28.2 V reverse standoff voltage sits just above the rail, so the diode stays out of conduction during normal operation but triggers before the downstream circuitry sees damaging overvoltage.
Package, temperature grade, and board integration
Housed in a DO-201AA (DO-27) axial-lead through-hole package, the 1.5KE33CABULK mounts into a 1.0 mm diameter hole on the PCB. The axial body allows the diode to be inserted vertically or bent over for low-profile layouts — common in telecom line cards and industrial PSU input stages where the TVS sits across the DC bus after the bridge rectifier. The operating junction temperature range spans -65°C to +175°C, covering military and industrial thermal extremes. The wide Tj margin means the diode can be placed near hot components (transformers, MOSFETs) without derating the pulse power capability at elevated ambient temperatures, though the 1500 W rating is specified at 25°C and derates linearly above that.
Sourcing and lifecycle posture
EIC Semiconductor lists the 1.5KE33CABULK as Active in production — the part is still in the current catalog and available through authorized distribution channels. The bag packaging (bulk) suits prototype builds and low-volume production runs where tape-and-reel feed is not required.