Obsolete — sourcing reality for the 1.5KE22C
The Littelfuse 1.5KE22C is officially marked Obsolete, meaning the manufacturer no longer produces this bidirectional Zener TVS diode.
What the 1500W peak pulse rating means for the BOM
The 49.7A peak pulse current (Ipp) at that waveform tells you the diode can shunt substantial fault energy without failing short. The 18.8V reverse standoff voltage (Vrwm) means this part begins conducting only when the line voltage exceeds that threshold, so it sits transparently on an 18V or lower rail. Breakdown occurs at 19.8V minimum, clamping the transient to 32.13V maximum — a tight enough window to protect 24V-rated ICs from overvoltage damage.
Package and deployment context
Housed in a DO-201AA (DO-27) axial-lead through-hole package — the same footprint used across the 1.5KE series. Single bidirectional channel means one device clamps both polarities, simplifying PCB layout on AC-coupled or bipolar DC lines. No power line protection feature — this is a secondary transient suppressor, not a primary mains protector.