Zener TVS for 376V rail protection
The STMicroelectronics P6KE440ARL is a 600W Zener transient voltage suppressor from the P6KE series, designed to clamp overvoltage transients on DC power rails and signal lines operating at up to 376V continuous. It is a unidirectional device in a DO-204AC (DO-15) axial-lead through-hole package, rated for general-purpose surge protection where a single channel is sufficient.
Voltage window and clamping behaviour
Breakdown occurs at a minimum of 418V, and the clamping voltage is held to a maximum of 776V at the rated peak pulse current of 5.2A (8/20µs waveform). This clamping ratio — 776V at 5.2A versus a 376V standoff — is typical for a Zener TVS; the design margin between the protected circuit's absolute maximum rating and the clamping voltage must be at least 776V to avoid damage during a surge event.
Power handling and surge capability
The 5.2A peak pulse current (8/20µs) is the current the part can safely shunt while clamping at 776V. No power line protection feature is included — this is a basic TVS diode, not a filtered or coordinated protector. Capacitance is 350pF at 1MHz, which may affect high-speed signal lines; for data-line protection, a lower-capacitance TVS or a steering-diode array is preferred.
The DO-15 axial package requires through-hole mounting with 0.040-inch (1.0 mm) diameter holes on a 0.300-inch lead spacing. Wave soldering or hand soldering is typical; the leads are tin-plated and solderable per standard IPC J-STD-001 profiles.
Cut Tape (CT) is also available for prototype or low-volume builds.