AEC-Q101 and the 150°C junction ceiling
AEC-Q101 qualification means this part has passed the automotive-grade stress tests: temperature cycling, high-temperature reverse bias, and ESD robustness per the standard. The DO-214AB (SMC) package footprint is the industry-standard outline for 1500W TVS diodes. The cathode tab on the top surface needs a thermal via array to the ground plane — the datasheet's recommended copper area under the tab directly sets the junction-to-ambient thermal resistance for repetitive pulse trains. This is a unidirectional device (one channel), meaning it clamps positive transients above the breakdown voltage while conducting the reverse polarity through the body diode. For a 24V automotive rail that sees reverse-battery events, a series blocking diode or a bidirectional TVS upstream is needed — the 1.5SMC39AHR6G alone does not protect against sustained reverse polarity.
The HR6G suffix specifically denotes the AEC-Q101 automotive grade in tape-and-reel packaging for automated assembly.