# SMD1812-350

**BORN** · Resettable Fuses · 1812

SMD1812-350 from BORN, in a 1812. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | 1 | passive | Non-polarized PPTC terminal (tin-plated nickel-copper) in series with the protected circuit, rated I-hold 3.50 A and I-trip 7.00 A at 25 °C, with Vmax of 6, 12 or 16 Vdc depending on the -350 variant. |
| 2 | 2 | passive | Second non-polarized PPTC terminal, interchangeable with the other terminal, rated I-hold 3.50 A and I-trip 7.00 A at 25 °C, with Imax of 100 A at Vmax. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | BORN |
| Package | 1812 |
| Category | Circuit Protection |
| Pins | 2 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Minimum resistance, initial un-soldered state (R0 min, 350/xx N family) | R0 | 0.008 |  |  | Ohm | Initial (un-soldered) state | 2 |
| Maximum resistance one hour after tripping or 260℃ reflow (R1 max, 350/xx N family) | R1 |  |  | 0.035 | Ohm | 25℃, one hour after tripping or reflow soldering of 260℃ for 20 sec | 2 |
| Holding current (I-hold) | I-hold |  |  | 3.5 | A | 25℃ still air; maximum current at which the device will not trip | 2 |
| Tripping current (I-trip) | I-trip | 7 |  |  | A | 25℃ still air; minimum current at which the device will trip | 2 |
| Maximum fault current withstand (Imax) | Imax |  |  | 100 | A | At rated voltage (Vmax) | 2 |
| Maximum time to trip |  |  |  | 4 | Sec. | At 10.00 A, 25 °C | 2 |
| Power dissipated in tripped state (Pd typ) | Pd |  | 1 |  | W | Tripped state, 25℃ still air (typical) | 2 |
| Operating temperature |  | -40 |  | 85 | °C |  | 3 |
| Maximum device surface temperature in tripped state |  |  |  | 125 | °C | Tripped state | 3 |
| Resistance change, passive aging |  | -5 |  | 5 | % | +85 °C, 1000 hours; typical resistance change | 3 |
| Resistance change, humidity aging |  | -5 |  | 5 | % | +85 °C, 85 % R.H., 1000 hours; typical resistance change | 3 |
| Resistance change, thermal shock |  |  | -30 |  | % | MIL-STD-202 Method 107, +85 °C to -40 °C, 20 times; typical resistance change | 3 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | Copper | tin | Terminal Material Tin-Plated Nickle-Copper (Solder Material: | 7 |

## CAD (KiCad official)

- Symbol: `SMD1812-350`
- Footprint: `Fuse:Fuse_1812_4532Metric`
- 3D model: 1812, generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 0.9 mm nominal _1806_ height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
- 3D model files: `smd1812-350-etched.step` / `smd1812-350-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smd1812-350.step` / `smd1812-350.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [BORN datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590922965750542336) (8 pp, sha256 `294e382d427046cd`, retrieved 2026-10-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/smd1812-350-datasheet.pdf)