P4SMAJ78A is an SMD transient voltage suppressor (TVS) diode designed for overvoltage and ESD protection in commercial and industrial applications. It features a stand-off voltage of 78 V with a peak pulse power dissipation of 400 W (10/1000 µs waveform) and steady-state power dissipation of 1 W at 75°C. The device operates over a junction temperature range of -50°C to +150°C and exhibits very fast response time with typical thermal resistance of 70 K/W (junction to ambient). The unidirectional configuration with SMA package (DO-214AC equivalent) makes it suitable for protecting sensitive circuits against transient overvoltage events, free-wheeling applications, and ESD protection in various electronic systems.