SMBJ40A is a unidirectional transient voltage suppressor diode designed for surge and ESD protection in compact surface-mount applications. This device features a working peak reverse voltage (V_RWM) of 40 V and a breakdown voltage range of 44.4 V to 49.1 V, with a maximum reverse leakage current of 10 µA at rated voltage. The SMBJ40A offers fast response times of less than 1.0 picosecond and is housed in the DO-214AA (SMB) package, enabling integration into space-constrained designs. With a maximum clamping voltage of 64.5 V and peak current handling capability of 9.3 A, this device provides robust protection against transient overvoltages in portable communications, computing, and video equipment. The SMBJ40A is RoHS compliant and conforms to JEDEC standards, making it suitable for IEC 61000-4-2 ESD, IEC 61000-4-4 EFT, and IEC 61000-4-5 surge protection applications.