What is the 1.5SMC440CA used for?
The 1.5SMC440CA is a bidirectional Zener-type TVS diode from Littelfuse's 1.5SMC series, designed to clamp transient overvoltages on a 376 V nominal rail.
Key ratings and what they mean for the BOM
The 376 V reverse standoff voltage (Vrwm) defines the maximum continuous DC or peak AC voltage the diode blocks without conducting — your rail must stay below this under steady-state conditions. The 418 V minimum breakdown voltage (Vbr) is where clamping starts; a 602 V maximum clamping voltage (Vc) at 2.5 A peak pulse current (Ipp) limits the transient spike seen by downstream components. Single bidirectional channel means one device protects a pair of rails or a single line referenced to ground, saving board space versus two unidirectional diodes in anti-series.
The supplier device package is listed as DO-214AB (SMCJ), confirming interchangeability with JEDEC SMCJ footprints on existing PCB layouts.