Clamping a 85.5V rail with 1500W peak pulse power
Its 1500W peak pulse power rating (1.5kW) at 10/1000µs waveform means it can absorb substantial surge energy before the clamping voltage reaches 137V at the peak current Ipp. That 137V ceiling is the hard stop — downstream silicon sees no more than that during the event.
onsemi lists the 1N6295AG as Obsolete. For BOM lines that still call this exact order code, the available stock is independent-distribution excess — franchised inventory is depleted.
Breakdown, standoff, and clamping window
The reverse standoff voltage is 85.5V — the rail voltage below which the diode is effectively off and leakage is minimal. That 42V window between standoff and clamp is the headroom the rail sees during a surge; a 12V bus would be overstressed, but a 72V or 85V telecom or industrial rail stays protected. That 175°C TJ max is the die limit, not the ambient — in a 85°C ambient enclosure, the derated peak pulse power is lower than the 1500W headline, so the thermal path through the leads and PCB copper matters for repetitive surge applications.