Protection profile — what the ratings mean for the circuit
The 1.5KE33C: The 28.2V reverse standoff voltage (working voltage) means the part does not conduct at normal rail levels up to that point. Clamping triggers at 29.75V minimum breakdown and holds the transient to 47.99V maximum at 33.3A peak pulse current — enough to protect a 24V DC bus or a 28V nominal line from surges without letting the spike exceed the downstream device's abs-max rating. The single bidirectional channel handles positive and negative transients in one package, simplifying layout for AC-coupled or floating lines. No power line protection feature (no internal filter), so this is a pure clamp — use it across the signal or supply pair, not as a standalone EMI suppressor.
Package and temperature grade — board-fit considerations
Supplied in a DO-201AA (DO-27) axial leaded package, through-hole mount. The DO-201 body handles the 1500W pulse without cracking the encapsulant, but the axial leads need through-hole plated holes on the PCB — not a surface-mount part. The wide range means derating for ambient temperature is minimal in most enclosures, but above 175°C the junction limit governs.
Sourcing the 1.5KE33C in an obsolete lifecycle
Given the Obsolete status, new-stock procurement is through surplus and broker channels. The 1.5KE series has many voltage variants, but a pin-compatible alternative from the same family would require the same 33V bidirectional rating. Request a quote for current availability and date code options.