Transient protection for 185 V rails
The P6KE220A-B is a 600 W unidirectional TVS diode in a DO-15 axial-lead package, designed to clamp transients on DC power rails and signal lines with a nominal 185 V operating voltage. The 185 V reverse standoff voltage (VRWM) means it sits across a 185 V bus without conducting leakage current under normal conditions, only triggering avalanche breakdown when a transient pushes the line above 209 V (minimum breakdown voltage).
Clamping performance and pulse handling
That clamping voltage is the ceiling the downstream circuitry must survive — a 185 V rail with a 328 V clamp gives a 143 V margin for the protected device's breakdown rating. For repetitive transients or longer pulse widths, derate per the datasheet's pulse-duration curve — the 600 W figure is a 1 ms benchmark, not a continuous rating. The wide junction range means the leakage current and clamping voltage shift with temperature — expect higher leakage at 175°C than at 25°C.
Package and board integration
The DO-15 (DO-204AC) axial package is through-hole mounted — leads insert into plated through-holes and are soldered on the opposite side. The axial body sits above the board, so the lead spacing (0.300 inch typical) must match the hole pattern on the PCB. Bulk packaging means the parts ship loose in a bag or tube, not taped and reeled. For automated insertion, a tape-and-reel variant (P6KE220A) may be preferred; the -B suffix indicates bulk packaging.