Clamping and standoff — what the voltage ratings mean for the protected rail
The 1.5SMC75CAHE3/9AT is a bidirectional TVS Zener (Transient Voltage Suppressor) in the DO-214AB (SMC) package, qualified to AEC-Q101 for automotive deployments. The standoff voltage of 64.1 V typ defines the working rail the diode monitors without conduction — the protected node sits below this in normal operation.
Automotive grade and thermal margin
Junction temperature rating is -65 to 150 °C. In an engine-compartment or chassis-domain layout the board-level ambient can reach 125 °C; the 150 °C Tj ceiling gives headroom above the typical automotive Grade 1 limit of 125 °C, so the part survives the upper end of the temperature band without derating below the rated peak pulse current. The "CA" suffix denotes bidirectional polarity; the "HE3" suffix is the Vishay halogen-free / RoHS-compliant AEC-Q101 grade designator for this series. The supplier device package field lists DO-214AB (SMCJ) — the SMC and SMCJ designations are the same outline; confirm the land pattern matches the board pad definition for the DO-214AB land pattern in the applicable IPC standard. Packaged as tape and reel — the standard orientation for automated SMT pick-and-place on high-volume automotive board assembly lines.
Listed Active by Vishay General Semiconductor — Diodes Division. The part is sourced to order; availability and lead time confirmed at RFQ. For automotive qualification programs requiring PPAP or IATF 16949 documentation, the component's AEC-Q101 qualification package is sourced through the manufacturer directly.