The STMicroelectronics P6KE15CA is a 600W bidirectional TRANSIL™ TVS diode in a DO-204AC (DO-15) axial-lead through-hole package. It is designed for general-purpose transient voltage suppression on unipolar or bipolar lines where the working voltage sits at 12.8V reverse standoff.
The 14.3V minimum breakdown voltage sets the threshold where the diode starts conducting — for a 12V nominal rail, this provides a guard band above the steady-state supply, so the device stays out of conduction during normal operation. The 27.2V maximum clamp at 147A (8/20µs waveform) defines the voltage the protected circuitry sees during a surge; a downstream DC-DC converter or linear regulator needs to survive that peak without damage. The 600W peak pulse rating is the energy-handling envelope for a single 10/1000µs pulse — derate for repetitive events or elevated ambient temperature.
ST has not issued a formal last-time-buy notice as of the current record, but the part is no longer the recommended choice for new board layouts.