The SMCJ40A is a unidirectional, bi-directional, or dual common mode transient voltage suppressor (TVS) diode, which provides protection against voltage transients in various applications, such as Ethernet, data lines, and CAN bus lines. It is designed to shunt a high-voltage spike to ground, allowing the device to pass current safely. This device features a rugged, low-capacitance silicon construction, and is rated for a maximum working peak reverse voltage up to 400 volts. It can withstand transient peak pulse currents up to 150 amps. The SMCJ40A also offers excellent surge suppression over the entire operating temperature range of -55 to 150C, making it an ideal choice for a wide range of applications.