600 W peak pulse, 170 V standoff — the rail protection number that matters
The SMBJ170A-13-F: That 600 W figure is the device's ability to absorb a transient without failing — it defines the energy the TVS can clamp before the junction temperature exceeds the silicon limit. With a 170 V reverse standoff voltage (VRWM), this part sits on a 170 V DC rail and stays transparent until a transient pushes the line above 189 V typical breakdown. The clamping voltage peaks at 275 V at the rated 2.2 A peak pulse current — meaning a 170 V bus sees the spike clipped to 275 V, which keeps downstream semiconductors inside their VDS or VCEO ratings.
DO-214AA SMB — footprint and reflow fit
Housed in the DO-214AA (SMB) surface-mount package, the SMBJ170A-13-F uses the standard JEDEC footprint shared by most SMB TVS diodes. The cathode band on the body marks the unidirectional orientation — the anode connects to the rail, cathode to ground, so the die avalanches on positive overvoltage events.