40V rail clamp with 600W pulse capacity
The SMBJ40A-13-F: It clamps a 40V reverse standoff rail at 64.5V max, with a breakdown voltage guaranteed between 44.4V and the clamp threshold.
Voltage stack and pulse current
The 40V reverse standoff is the continuous DC voltage the TVS blocks without conducting. Breakdown starts at 44.4V min, and the clamp voltage peaks at 64.5V at the rated 9.3A peak pulse current. This 24.5V window between standoff and clamp means a 48V bus or a 36V rail with transients up to 64.5V is within the device's protection envelope. For shorter pulses (8/20µs) the peak power capability is higher; derate above 25°C per the datasheet curve.
Package and board-fit
The SMB footprint is larger than the SMA sibling, offering better thermal dissipation for the 600W pulse. The cathode band on the package body marks the unidirectional orientation. The tape-and-reel packaging suits high-volume pick-and-place assembly.
Marked as Active on the lifecycle record. No end-of-life notice or successor part is on file.