# SRF1812P050

**prosemi** · Resettable Fuses · 1812

SRF1812P050 from prosemi, 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 PTC resettable fuse (one end-cap pad, recommended pad 1.78±0.1 mm x 3.15±0.1 mm), rated hold current 0.50 A, trip current 1.00 A, Vmax 60 V. |
| 2 | 2 | passive | Second terminal of the non-polarized PTC resettable fuse (other end-cap pad, 3.45±0.1 mm pad gap), rated hold current 0.50 A, trip current 1.00 A, Vmax 60 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | prosemi |
| 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 (max, will not trip at 25°C still air) | IH |  |  | 0.5 | A | 25°C still air, after one reflow; per definition IH = maximum current at which the device will not trip | 1 |
| Trip current (min, will always trip at 25°C still air) | IT | 1 |  |  | A | 25°C still air; per definition IT = minimum current at which the device will always trip | 1 |
| Maximum continuous voltage | Vmax |  |  | 60 | V | Maximum continuous voltage device can withstand without damage at rated current | 1 |
| Maximum fault current | Imax |  |  | 40 | A | Maximum fault current device can withstand without damage at rated voltage | 1 |
| Minimum resistance in initial (un-soldered) state | Rmin | 0.15 |  |  | Ω | Initial un-soldered state | 1 |
| Maximum resistance at 25°C one hour after reflow | R1max |  |  | 1.4 | Ω | 25°C, measured one hour after reflow | 1 |
| Hold current at ambient -40°C (thermal derating chart) | IH |  | 0.69 |  | A | Ambient operating temperature -40°C | 1 |
| Hold current at ambient -20°C (thermal derating chart) | IH |  | 0.59 |  | A | Ambient operating temperature -20°C | 1 |
| Hold current at ambient 0°C (thermal derating chart) | IH |  | 0.55 |  | A | Ambient operating temperature 0°C | 1 |
| Hold current at ambient 25°C (thermal derating chart) | IH |  | 0.5 |  | A | Ambient operating temperature 25°C | 1 |
| Hold current at ambient 40°C (thermal derating chart) | IH |  | 0.45 |  | A | Ambient operating temperature 40°C | 1 |
| Hold current at ambient 50°C (thermal derating chart) | IH |  | 0.43 |  | A | Ambient operating temperature 50°C | 1 |
| Hold current at ambient 60°C (thermal derating chart) | IH |  | 0.35 |  | A | Ambient operating temperature 60°C | 1 |
| Hold current at ambient 70°C (thermal derating chart) | IH |  | 0.3 |  | A | Ambient operating temperature 70°C | 1 |
| Hold current at ambient 85°C (thermal derating chart) | IH |  | 0.23 |  | A | Ambient operating temperature 85°C | 1 |

## CAD (KiCad official)

- Symbol: `SRF1812P050`
- 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: `srf1812p050-etched.step` / `srf1812p050-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `srf1812p050.step` / `srf1812p050.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [prosemi datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590918761941708800) (3 pp, sha256 `0f89034024a1602c`, 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/srf1812p050-datasheet.pdf)