Breakdown voltage and clamping — what the numbers mean for your rail
The 1N6170A is a bidirectional Zener TVS diode from Microchip Technology, rated for a reverse standoff voltage of 114 V. That standoff is the maximum DC or peak AC voltage the device can sit across without conducting — above it the diode starts to break down, clamping the transient. The minimum breakdown voltage is 142.5 V, so on a 114 V nominal rail the device stays off until a surge pushes the rail past that threshold. When it does fire, the clamping voltage is 206.3 V at a peak pulse current of 7.3 A under the standard 10/1000 µs waveform. That 206.3 V is the voltage the protected circuitry must survive — if your downstream MOSFET or controller is rated for 200 V absolute max, this clamp is too tight; you need a higher standoff part.
1500 W peak pulse — sizing the surge energy
The 1N6170A is rated for 1500 W peak pulse power under the 10/1000 µs waveform — that is the energy the device can absorb in a single surge event without failing. For a 114 V rail, 1500 W translates to a peak current of about 7.3 A, which is the current the device shunts during the clamp. If your application sees repetitive surges or longer pulse widths, derate the peak power per the datasheet pulse derating curve.
That 175°C ceiling matters for avionics, downhole tools, and outdoor telecom enclosures where ambient heat plus self-heating from the surge pushes junction temperature well above 125°C. The through-hole Axial package handles the thermal dissipation better than a surface-mount equivalent — the leads conduct heat into the PCB copper and the air around the body.
Bidirectional — one device, both polarities
The 1N6170A is a single bidirectional channel, meaning it clamps transients of either polarity. That is useful on AC-coupled data lines (RS-485, Ethernet magnetics) or on floating DC rails where the signal swings through zero. No power line protection — this is a signal- or low-power-rail TVS, not a mains surge suppressor.
Lifecycle and sourcing — active, quoted to order
The part is sourced per RFQ against the BOM quantity — no stock-holding claim, no immediacy promise. The Axial package is a through-hole form factor, which is a mature, widely stocked footprint. For volume pricing and lead time, submit an RFQ with the target quantity and date-code preference.