# SMD1812B300TFT

**Brightking** · Resettable Fuses · 1812

SMD1812B300TFT from Brightking, 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 | Terminal 1 of an unpolarised fuse; either orientation. |
| 2 | 2 | passive | Terminal 2 of an unpolarised fuse; either orientation. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Brightking |
| 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 |
|---|---|---|---|---|---|---|---|
| Trip current (minimum) | Itrip | 5 |  |  | A | 23℃ still air | 2 |
| Minimum resistance (un-soldered initial state) | Rmin | 0.012 |  |  | Ω | Initial un-soldered state | 2 |
| Hold current (maximum) | Ihold |  |  | 3 | A | 23℃ still air | 2 |
| Maximum voltage | Vmax |  |  | 6 | Vdc | At rated current (Imax) | 2 |
| Maximum fault current | Imax |  |  | 100 | A | At rated voltage (Vmax) | 2 |
| Maximum time to trip |  |  |  | 4 | s | At 8.00 A | 2 |
| Maximum resistance after trip or reflow | R1max |  |  | 0.04 | Ω | 23℃, measured one hour after tripping or reflow soldering at 260℃ for 20 sec | 2 |
| Passive aging resistance change (typical) |  | -50 |  | 50 | % | +85℃, 1000 hours; typical resistance change | 9 |
| Humidity aging resistance change (typical) |  | -50 |  | 50 | % | +85℃, 85%R.H., 1000 hours; typical resistance change | 9 |
| Thermal shock resistance change (typical) |  | -50 |  |  | % | MIL-STD-202 Method 107G, -40℃ to +85℃, 20 times; typical resistance change | 9 |
| Operating / storage temperature |  | -40 |  | 85 | ℃ | Operating / storage temperature | 9 |
| Maximum device surface temperature in tripped state |  |  |  | 125 | ℃ | Tripped state | 9 |
| Power dissipated in tripped state (typical) | Pd typ. |  | 0.8 |  | W | Tripped state at 23℃ still air | 2 |
| Recommended hold current at ambient -40℃ |  |  | 4.13 |  | A | Ambient -40℃ | 5 |
| Recommended hold current at ambient -20℃ |  |  | 3.75 |  | A | Ambient -20℃ | 5 |
| Recommended hold current at ambient 0℃ |  |  | 3.3 |  | A | Ambient 0℃ | 5 |
| Recommended hold current at ambient 23℃ |  |  | 3 |  | A | Ambient 23℃ | 5 |
| Recommended hold current at ambient 40℃ |  |  | 2.62 |  | A | Ambient 40℃ | 5 |
| Recommended hold current at ambient 50℃ |  |  | 2.43 |  | A | Ambient 50℃ | 5 |
| Recommended hold current at ambient 60℃ |  |  | 2.25 |  | A | Ambient 60℃ | 5 |
| Recommended hold current at ambient 70℃ |  |  | 2 |  | A | Ambient 70℃ | 5 |
| Recommended hold current at ambient 85℃ |  |  | 1.78 |  | A | Ambient 85℃ | 5 |

## 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 Solder-Plated Copper (Solder Material: Matte Tin (Sn)) | 10 |

## CAD (KiCad official)

- Symbol: `SMD1812B300TFT`
- 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: `smd1812b300tft-etched.step` / `smd1812b300tft-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smd1812b300tft.step` / `smd1812b300tft.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Brightking datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588903002434375680) (11 pp, sha256 `341444dcfc3f77f4`, retrieved 2026-10-19, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins`, primary `two-terminal convention` (convention), consensus `off` (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/smd1812b300tft-datasheet.pdf)