1500 W peak pulse — the protection envelope
The 1.5KE22: The corresponding peak pulse current is 49.7 A at the same 10/1000 µs condition, which sets the maximum surge current the diode can clamp without failing. The reverse standoff voltage is 18.8 V, meaning the diode draws negligible leakage below that rail voltage and only starts conducting significantly above the minimum breakdown of 19.8 V.
Unidirectional Zener — polarity matters
This is a unidirectional Zener TVS (single channel), so it protects one polarity rail — the cathode is tied to the positive line, anode to ground. It will not clamp bidirectional transients; for AC or bipolar lines you would need a bidirectional part from the same 1.5KE series.
Sourcing posture for the 1.5KE22
Because this part is obsolete, it is not stocked in volume by the manufacturer. We source it through independent surplus and broker channels — each lot is verified for authenticity and RoHS compliance before shipment. Pricing and availability are confirmed at quote time against your BOM quantity. No official cross-reference or pin-compatible second source is listed by Littelfuse. If you need a drop-in replacement, a parametric search on the 1.5KE series for a similar standoff voltage and same package is the starting point — but a full electrical comparison of the clamping and breakdown specs is required before substituting.