1500W bidirectional Zener TVS — 145V standoff, 234V clamp
The 1.5KE170CA-B: The 145V standoff means the part stays transparent on a nominal 120V or 130V rail — it only begins conducting when the transient exceeds the breakdown threshold. The 234V clamp ceiling protects downstream silicon rated for 250V or less, which covers most 120VAC secondary-side rectifier buses and 48V telecom rails.
Obsolete — no successor on record from Diodes
Diodes Incorporated lists the 1.5KE170CA-B as Obsolete. No official successor order code is published — the 1.5KE series itself is the reference, but specific voltage/package variants within it may also face end-of-life. For a BOM that already carries this part, the procurement path is independent-distribution surplus or broker channel, not a franchised new-production buy. The junction temperature range spans -55°C to 175°C, which covers outdoor telecom cabinets, industrial control enclosures, and under-hood automotive modules that see sustained heat soak. The DO-201AA/DO-27 axial leaded package is through-hole — it survives rework and field replacement cycles better than a surface-mount TVS in the same power class.
Bidirectional, single-channel — no power-line protection
The bidirectional channel clamps both polarities with a single device, which saves board space on AC-coupled signal lines or bipolar DC rails. For 120/230VAC primary-side protection, a varistor or higher-voltage TVS in a larger package is the correct choice. The 6.4A peak pulse current at 10/1000µs is the current the device can sink during the clamp event. At the 1500W peak power level, the junction temperature rise during the pulse is the limiting factor — the 175°C TJ max sets the derating curve above 25°C ambient. In a 85°C enclosure, the effective peak pulse power drops to roughly 60% of the 1500W rating.