Obsolete — sourcing the 1.5KE22CA now
For BOM lines that still specify this part, supply is limited to existing stock in the independent distribution channel. Sourcing this device now means buying from surplus inventory — date codes will vary, and each reel or tube should be inspected for marking consistency and package integrity before populating a board.
20.9 V breakdown — what it protects
This is a bidirectional single-channel TRANSIL™ TVS diode from the 1.5KE series, rated for 1500 W peak pulse power (1.5 kW) per the 10/1000 µs waveform. The minimum breakdown voltage is 20.9 V, with a reverse standoff of 18.8 V and a maximum clamping voltage of 39.3 V at the peak pulse current of 254 A (tested with the 8/20 µs waveform). The 1850 pF capacitance at 1 MHz matters when this part sits on a data line — it will load the signal, so it is better suited for power rails or slower I/O than high-speed differential pairs.
DO-201 axial — through-hole mounting
The package is DO-201AA / DO-27 axial leaded, through-hole mount. This is a larger-bodied axial diode — the leads need to be formed to the PCB hole spacing. No power line protection is built in; this is a general-purpose transient suppressor for secondary-side protection on DC buses, relay coils, or low-frequency AC lines.