What the 1.5SMCJ36 does on a board
The 1.5SMCJ36 is a unidirectional Zener-based TVS diode in the DO-214AB (SMC) package — a workhorse transient suppressor that clamps voltage spikes on signal and control lines without disturbing the normal rail. Rated 36V reverse standoff (typ), it breaks down at 40V minimum and clamps at 64.3V max during a 10/1000 µs surge event, absorbing up to 1.5 kW peak pulse without degradation. This is not a power-line protector (confirms power line protection is listed No), so it sits on the board side of the supply, clamping reflected transients before they reach downstream ICs.
36V standoff sets the maximum working rail this TVS can sit across without conduction — it stays reverse-biased and invisible on a 24V nominal rail with headroom to spare. The 150°C maximum junction temperature is the constraint that drives the thermal pad design: the DO-214AB epoxy body is the thermal bottleneck, and the board copper under the pad is the primary heatsink path. Keeping Tj below 150°C in a still-air box layout means budgeting at least a couple of square centimeters of 2 oz copper around the device footprint. Surface-mount TO-277 successor package for higher-density layouts — the DO-214AB SMC footprint is industry-standard and mates with the same pick-and-place nozzles used across the rest of the SMC family. The unidirectional polarity means one pin is cathode (bar) and one is anode — polarity is marked by the bar on the package, which is legible under magnification on a rework bench.
Listed Active by Diotec Semiconductor. Quoted to order through independent distribution against an RFQ; availability and volume pricing confirmed at quote time.