The STMicroelectronics 1.5KE440CA is a 1500 W bidirectional transient voltage suppressor from the TRANSIL™ series, designed to clamp transients on AC mains, DC power buses, and signal lines where the normal operating voltage stays at or below 376 V. The device is a Zener-type TVS, not a standard rectifier: it conducts sharply at the breakdown voltage (418 V minimum) and clamps the let-through to 776 V maximum at the rated peak pulse current of 13 A for the 10/1000 µs waveform, also characterized at 8/20 µs. This is a single bidirectional channel, so it clamps both polarities symmetrically — useful for AC-coupled or bipolar rails where a unipolar part would need two devices back-to-back.
1500 W peak pulse — sizing the surge margin
The 1500 W peak pulse power (1.5 kW) at 10/1000 µs is the headline surge rating. For a 376 V rail, the 13 A peak pulse current means the part can absorb a transient that would otherwise punch through a downstream regulator or driver. The 8/20 µs waveform rating (also 13 A) covers faster ESD or lightning-induced events per IEC 61000-4-5. If your expected transient energy exceeds 1500 W for the given pulse width, you need a higher-power device in the 1.5KE family or a parallel array. The 180 pF capacitance at 1 MHz is low enough for most power and signal lines but may load high-speed data buses above a few MHz.
DO-201 axial — through-hole mounting and board fit
The 1.5KE440CA comes in a DO-201AA / DO-27 axial-lead package, through-hole mount. The body is cylindrical with formed leads for insertion into a plated through-hole. The DO-201 footprint is standard for 1.5 kW TVS devices; the axial leads handle the surge current without trace lift-off if the PCB copper is sized for the peak current. Cut Tape (CT) and Tape & Box (TB) packaging options are available for different assembly flows.
The base product number is 1.5KE440; the suffix CA indicates a bidirectional device (the A suffix alone would be unipolar).