# SMD1812-075-24

**hongjiacheng** · Resettable Fuses · 1812

SMD1812-075-24 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 | First terminal of the non-polarized PPTC device (Ihold 0.75 A, Itrip 1.5 A, Vmax 24 V, Imax 40 A); the drawing shows two end terminals with no polarity, so terminals are interchangeable. |
| 2 | 2 | passive | Second terminal of the non-polarized PPTC device (Ihold 0.75 A, Itrip 1.5 A, Vmax 24 V, Imax 40 A); the drawing shows two end terminals with no polarity, so terminals are interchangeable. |

## 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 |
|---|---|---|---|---|---|---|---|
| Hold current (Ihold) | Ihold |  |  | 0.75 | A | 25℃ still air (maximum current passed without tripping) | 2 |
| Trip current (Itrip) | Itrip | 1.5 |  |  | A | 25℃ still air (minimum current at which device trips) | 2 |
| Maximum voltage (Vmax) | Vmax |  |  | 24 | V | At rated current (Imax) | 2 |
| Maximum fault current (Imax) | Imax |  |  | 40 | A | At rated voltage (Vmax) | 2 |
| Power dissipated in tripped state (Pd typ.) | Pd |  | 0.8 |  | W | Tripped state, 25℃ still air | 2 |
| Maximum time-to-trip |  |  |  | 8 | Sec |  | 2 |
| Minimum resistance, initial state (Ri min) | Ri | 0.2 |  |  | Ω | Initial (un-soldered) state | 2 |
| Maximum resistance at 25℃ after trip or reflow (R1 max) | R1 |  |  | 0.45 | Ω | 25℃, measured one hour after tripping or reflow soldering of 260℃ for 20 sec | 2 |
| Operating / storage temperature |  | -40 |  | 85 | ℃ |  | 5 |
| Maximum device surface temperature in tripped state |  |  |  | 125 | ℃ | Tripped state | 5 |
| Peak reflow temperature (TP) | TP |  |  | 260 | ℃ | Printed as +260(+0/-5)℃; Pb-free assembly reflow profile | 1 |

## CAD (KiCad official)

- Symbol: `SMD1812-075-24`
- 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: `smd1812-075-24-etched.step` / `smd1812-075-24-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `smd1812-075-24.step` / `smd1812-075-24.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [hongjiacheng datasheet](docs/smd1812-075-24-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/smd1812-075-24-datasheet.pdf)