TVS clamping and pulse power rating
The 1.5SMC170CA-M3/9AT: The 145 V reverse standoff (working voltage) means the diode draws negligible leakage below that level, and only begins conducting when the transient exceeds the minimum breakdown of 162 V.
Housed in the DO-214AB (SMC) package, the device is surface-mount with a large copper tab that transfers heat to the PCB copper plane. Supplied in Tape & Reel (TR), it suits high-volume pick-and-place assembly. The bidirectional configuration means a single device protects both polarities — no need to orient the cathode, simplifying placement and reducing BOM line count for AC or bipolar DC lines.