Obsolete part, still specifiable — the P6KE22CA-T sourcing picture
Diodes Incorporated lists the P6KE22CA-T as Obsolete.
The 18.8V reverse standoff voltage means the diode draws negligible leakage current on a nominal 18V or lower rail. The 20.9V minimum breakdown voltage guarantees avalanche conduction begins before the protected node exceeds ~21V. The 30.6V clamp is the voltage the load sees during a 20A surge — the downstream IC's abs-max rating must sit above this level with margin.
Supplied in DO-204AC (DO-15) axial leaded package, through-hole mount. The 0.032-inch diameter leads solder into 0.040-inch plated through-holes on a standard 2.54mm pitch grid. No moisture sensitivity level (MSL) applies — axial devices are not moisture-sensitive.