The 1.5SMC39AHE3/57T is a Zener-type transient voltage suppressor from Vishay's 1.5SMC series, branded TransZorb®. It is qualified to AEC-Q101, making it suitable for automotive-grade applications where reliability under temperature extremes and surge events is required. The reverse standoff voltage is 33.3 V, providing margin for 24 V or 28 V DC rails. Breakdown voltage is guaranteed at a minimum of 37.1 V, ensuring the TVS begins conducting before the protected circuitry sees an overvoltage condition. The single unidirectional channel means polarity must be observed on DC lines.
The wide range also supports high-reliability designs where ambient temperature may exceed 85°C.