What this Zener TVS diode does — 600W surge clamp in a T-18 axial body
The P6KE43ARL: It clamps transients at 59.3V max when the surge current hits 10.1A (8/20 µs). Reverse standoff voltage is 36.8V typical — this is the DC rail voltage the diode will not conduct under normal operation. Breakdown occurs at 40.9V minimum, so a 36V supply rail sits comfortably below the clamping threshold. The T-18 axial package is a through-hole body suited for point-to-point wiring or PCB mounting where the lead bend absorbs board stress.
onsemi lists the P6KE43ARL as Obsolete. For BOM lines that still call out this exact order code, supply is limited to existing distributor inventory and the spot market. Confirm the date code and storage condition before committing to a reflow or wave-solder process.
600W peak pulse power is the maximum energy the diode can absorb in a single transient event — enough for secondary protection on 24V to 36V DC rails in industrial controls, telecom line cards, or power supplies. The 59.3V clamping voltage sets the upper bound the downstream circuitry must survive. No power line protection means this part is not rated for AC mains surge suppression — it is a signal-rail or low-voltage DC rail protector. The single unidirectional channel handles one polarity; for bipolar lines you need two devices back-to-back or a bidirectional variant.