5KP series unidirectional Zener TVS in P600 axial
The 5KP18A/B is a unidirectional Zener-based transient voltage suppressor from YAGEO's 5KP series, housed in the P600 axial through-hole package and rated for general-purpose circuit protection. The single-channel device clamps a surge once the line voltage exceeds its breakdown threshold, protecting downstream components from overvoltage events on the primary rail.
What the standoff, breakdown, and clamping ratings mean
The reverse standoff voltage of 18 V typical defines the working voltage the diode sees in normal operation — the part stays off and introduces no clamping action below that level.
Peak pulse energy and what 5 kW means for surge survival
That waveform shape is the standard industrial surge test profile for secondary protection on power rails. A 174.7 A peak pulse current flows through the diode at that rated event; the part survives it without degradation when the event is within the specified pulse width and repetition limits in the datasheet.
Wide junction temperature range for industrial environments
The through-hole P600 axial leadform makes it suited for board-level insertion with hand or wave solder, and the leaded package provides thermal relief through the leads that a surface-mount part of equivalent surge rating would not.
The part carries no power-line protection designation — it is a secondary protection device intended for board-level overvoltage suppression, not a mains-fed service entry protector.