# SMD1812-260-12

**hongjiacheng** · Resettable Fuses · 1812

SMD1812-260-12 from hongjiacheng, 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 | One terminal of the non-polarized PTC device (left pad of the 1812 body, 1.7±0.1 mm pad on a 3.0±0.1 mm gap); rated Ihold 2.60A, Itrip 5.0A, Vmax 12V, Imax 40A for SMD1812-260-12. |
| 2 | 2 | passive | Other terminal of the non-polarized PTC device (right pad of the 1812 body, 1.7±0.1 mm pad, 3.5±0.1 mm pad height); current passes in either direction with Ri min 0.01 ohm and R1 max 0.07 ohm. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | hongjiacheng |
| 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 in initial (un-soldered) state (Ri min) | Ri | 0.01 |  |  | Ω | initial (un-soldered) state | 3 |
| Maximum resistance at 25℃ after trip or reflow (R1 max) | R1 |  |  | 0.07 | Ω | 25℃, measured one hour after tripping or reflow soldering of 260℃ for 20 sec | 3 |
| Trip current (Itrip), minimum | Itrip | 5 |  |  | A | 25℃ still air | 3 |
| Hold current (Ihold), maximum current without tripping | Ihold |  |  | 2.6 | A | 25℃ still air | 3 |
| Maximum voltage withstand (Vmax) | Vmax |  |  | 12 | V | at rated current (Imax) | 3 |
| Maximum fault current withstand (Imax) | Imax |  |  | 40 | A | at rated voltage (Vmax) | 3 |
| Max. time-to-trip |  |  |  | 2.5 | Sec | paired current column 8.0 A | 3 |
| Typical power dissipated in tripped state (Pd typ) | Pd |  | 0.8 |  | W | tripped state, 25℃ still air | 3 |
| Operating / storage temperature |  | -40 |  | 85 | ℃ | operating / storage | 5 |
| Maximum device surface temperature in tripped state |  |  |  | 125 | ℃ | tripped state | 5 |

## CAD (KiCad official)

- Symbol: `SMD1812-260-12`
- 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: `smd1812-260-12-etched.step` / `smd1812-260-12-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smd1812-260-12.step` / `smd1812-260-12.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [hongjiacheng datasheet](docs/smd1812-260-12-datasheet.pdf) (6 pp, sha256 `8ab1f213bc6d6cd2`, retrieved 2026-10-19, 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/smd1812-260-12-datasheet.pdf)