The SMAJ51A is a unidirectional transient voltage suppressor diode designed for surge and ESD protection in portable communications, computing, and video equipment. It features a working peak reverse voltage of 51 V with a breakdown voltage range of 60.7 V to 66.3 V, and is housed in a compact DO-214AC (SMA) surface mount package. The device delivers 400 watts peak pulse power dissipation at 1 ms pulse width and maintains steady-state power dissipation of 1.0 watt at 75°C lead temperature. With fast response times of less than 1.0 picosecond and maximum clamping voltage of 82.4 V at 4.9 A, the SMAJ51A provides reliable protection against transient overvoltages while meeting IEC 61000-4-2 ESD, IEC 61000-4-4 EFT, and IEC 61000-4-5 surge standards. Its RoHS compliance and UL recognition make it suitable for demanding industrial and consumer applications requiring robust transient protection.