SMCJ78A-Q is an automotive-grade transient voltage suppressor diode designed for surge and ESD protection applications in compact SMC (DO-214AB) surface mount package. The device features a standoff voltage of 78V with a peak power dissipation rating of 1500 watts, providing robust protection for power buses and I/O interfaces. It exhibits typical fast response times of less than 1.0 picosecond from 0V to breakdown voltage, ensuring rapid transient suppression. The SMCJ78A-Q is RoHS compliant and AEC-Q101 automotive qualified, making it suitable for telecom, computer, industrial, consumer electronics, and automotive entertainment and comfort applications where reliable overvoltage transient protection is critical.