The SMBJ5.0A is a 600W peak pulse power transient voltage suppression (TVS) diode in SMB package, unidirectional, with 5.0V working voltage (VRWM). In normal operation below 5.0V, the diode draws only microamps of leakage current (typically 50uA at VRWM). When a transient voltage exceeds the breakdown voltage (VBR = 6.40-7.07V at 1mA), the TVS diode avalanches and clamps the voltage. At the peak pulse current (IPP = 53A for 10/1000us waveform), the clamping voltage is 9.2V maximum. The 600W rating refers to the peak pulse power dissipation (VCL x IPP = 9.2V x 53A = 488W, derated to 600W at lower currents). The A suffix indicates unidirectional (protects against positive transients only; for bidirectional protection, use SMBJ5.0CA). The unidirectional device also protects against negative transients by forward-biasing the diode, clamping at approximately -1.5V. The SMB package (DO-214AA) is smaller than SMC but larger than SOD-123, with typical footprint of 4.3×3.6mm. The device meets IEC 61000-4-2 ESD protection of +/-30kV (contact discharge) and IEC 61000-4-5 surge protection. Typical applications include 5V power supply input protection, USB port ESD protection, and general-purpose I/O line protection. The junction capacitance is 250pF typical at 0V, which limits its use on high-speed signal lines.