TVS Diode, Bidirectional, 24V, 38.9V, DO-214AA (SMB) - 

The Transil SMBJ series from STMicroelectronics are transient voltage suppressing diodes. These diodes are used to protect sensitive equipment against electrostatic discharges and electrical over stress. Transil SMBJ series are generally used against surges below 600W (10/1000 μs). Planar technology makes these devices suitable for high end equipment and SMPS where low leakage current and high junction temperature are required. These devices are packaged in SMB footprint in accordance with IPC 7531 standard.