Thermal and environmental envelope
The 1.5SMC6.8CAHM3/H: Junction temperature is rated -65 to +150 °C — that top end is the rating that matters for under-hood automotive deployments where the board ambient can spike well above 85 °C ambient. The -65 °C cold start capability covers equipment that must function before the engine warms up. Surface-mount DO-214AB (SMC) packaging handles the board-level thermal cycling; the TransZorb construction gives the junction some immunity to moisture ingress compared to a plain Zener pellet.
Automotive and telecom deployment context
AEC-Q101 qualification means this part has passed the automotive board-level stress battery — temperature cycling, humidity, surge, and mechanical shock. For telecom 48 V rail protection, the same 6.45–10.5 V clamping window protects sensitive PHY and RS-485 interface ICs that run on 5 V rails.