What the 600W peak pulse rating means on the bench
The P6KE220CA-B: On a repair bench, if the scorch mark is on the TVS itself, the incoming surge exceeded that budget and the die shorted. Bidirectional single channel means one DO-15 body covers both positive and negative transients — no need to pair two unidirectional parts back-to-back. Saves a solder joint and a BOM line.
Clamping voltage and the downstream silicon it protects
Reverse standoff is 185V — the rail sits below this in normal operation and the TVS is effectively open. That 328V ceiling is what the downstream MOSFET or IC must survive; if the DC-DC converter's abs-max is 300V, this TVS won't save it on a fast transient.
Package and board-fit for the rework station
DO-204AC / DO-15 axial leaded package — through-hole mount, two leads, no orientation worries on a bidirectional part. Hand-solderable in under 30 seconds with a standard iron; no hot-air profile needed. The Bulk packaging means loose tubes or bag, not tape-and-reel — fine for bench stock, less convenient for pick-and-place. No power line protection claim — this is a signal-line or low-power rail TVS, not a mains surge suppressor. Keep it on the secondary side of the PSU.
No stock-holding claim — confirmed per RFQ.