TVS diode for 1500W transient protection
The 1.5SMC200A-E3/9AT: It clamps transients at 274V maximum when hit with a 5.5A peak pulse current, and its 171V reverse standoff voltage means it stays out of the circuit during normal 150V–170V rail operation. The 190V minimum breakdown voltage gives a clean trigger threshold.
Clamp voltage and peak current — the real protection envelope
For a 171V nominal rail, the 103V headroom between standoff and clamp means the TVS absorbs the transient without letting the voltage spike damage downstream components. The 1500W peak pulse rating is the energy-handling ceiling — derate for higher ambient temperatures per the datasheet curve. This is a unidirectional device (one channel), so it protects a single polarity rail. For AC or bidirectional lines, two devices or a bidirectional variant would be needed. The 190V minimum breakdown ensures the TVS triggers before the protected circuit's own voltage rating is exceeded.
The DO-214AB (SMC) package is a standard surface-mount footprint for TVS diodes in this power class. Tape-and-reel packaging (Cut Tape also available) suits automated pick-and-place assembly. No power line protection (no internal filter), so this is a pure transient clamp, not a line conditioner.