The STMicroelectronics 1.5KE220CARL is a bidirectional 1500W transient-voltage-suppression (TVS) Zener from the 1.5KE TRANSIL™ series, packaged in a DO-201AA / DO-27 axial-lead through-hole case. It is officially listed as Obsolete. That means ST has stopped production; no last-time-buy window remains open through the factory. Any procurement for this order code goes through the independent surplus and broker channel, where date-code provenance and lot traceability need checking before the reflow oven.
Key ratings — the numbers that matter
Peak pulse power is 1500W (1.5kW) for a 10/1000 µs waveform, with a peak pulse current of 26A (8/20 µs waveform). The reverse standoff voltage is 188V; breakdown occurs at a minimum of 209V. Clamping voltage at rated Ipp is 388V. That 388V clamp is the ceiling your downstream silicon sees — it needs to survive that peak without secondary breakdown.
Bidirectional — one device, both polarities
This is a single bidirectional channel, meaning symmetrical clamping in both directions from a single die. No polarity marking to worry about on the board — it lands either way in the through-hole pads.
Where it goes — general-purpose surge protection
Rated for general-purpose applications — think AC/DC power rails, industrial control inputs, motor-drive bus protection, or any 188V nominal line that needs a 1500W transient absorber. Through-hole DO-201 package suits point-to-point wiring on terminal blocks or PCB edge guards. No power-line protection rating (not UL1449 listed), so it is a component-level TVS, not a certified surge protector.