Transient suppressor with a known trigger and clamp
The 1.5KE200-E3/54: A single unidirectional channel in a through-hole DO-201AA (DO-27) axial package, rated for continuous junction temperature from -55°C to 175°C. No power-line protection feature — it's a straightforward transient-voltage suppressor for general-purpose DC bus or signal-line clamping.
What the clamping envelope means for your circuit
Above 180 V (VBR min), the device begins to avalanche, and at 5.2 A of surge current it holds the line to 287 V (VC max). The 1500 W peak pulse rating is tested with a 10/1000 µs exponential waveform — the standard telecom surge. For shorter pulses (8/20 µs) the peak power capability is higher; the datasheet's pulse-derating curve governs the actual safe operating area. The 5.2 A IPP at the 1000 µs tail is the worst-case current the diode shunts to ground.
Obsolete — sourcing through independent channels
Sourcing goes through independent surplus and broker channels. Stock is lot-specific; quantities, date codes, and pricing are confirmed at RFQ. No pin-compatible replacement from Vishay is documented — a BOM substitution requires comparing the VRWM and clamping voltage against an active TVS family.