# SF-1206S125-2

**BOURNS** · Disposable Fuses · 1206

SF-1206S125-2 from BOURNS, in a 1206. 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 | BOURNS |
| Package | 1206 |
| 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 |
|---|---|---|---|---|---|---|---|
| Clearing time at 250 % of rated current |  |  |  | 5 | s | Clearing time at 25 °C ambient, 250 % of rated current (series characteristic) | 1 |
| Clearing time at 100 % of rated current |  | 4 |  |  | h | Clearing time at 25 °C ambient, 100 % of rated current (series characteristic) | 1 |
| Resistance tolerance |  | -25 |  | 25 | % | Resistance measured with ≤10 % rated current at 25 °C ambient | 1 |
| Resistance |  |  | 0.09 |  | Ω | Measured with ≤10 % rated current at 25 °C ambient | 1 |
| Rated current |  |  | 1.25 |  | A |  | 1 |
| Rated voltage |  |  |  | 63 | VDC | Rated voltage for SF-1206S125-2 | 1 |
| Interrupting rating |  |  |  | 50 | A | @ 63 VDC | 1 |
| Operating temperature |  | -20 |  | 105 | °C | Operating temperature range | 1 |
| Storage temperature |  | 5 |  | 35 | °C | Storage conditions | 1 |
| Fusing time |  |  |  | 5 | s | 200 % of rated current | 4 |
| Temperature rise |  |  |  | 75 | °C | 100 % of rated current, surface temperature | 4 |
| Resistance change after resistance to solder heat | ΔR | -20 |  | 20 | % | 260 °C ±5 °C, 10 seconds ±1 second | 4 |
| Resistance change after resistance to dry heat | ΔR | -20 |  | 20 | % | 105 °C ±5 °C, 1000 hours | 4 |
| Resistance change after thermal shock | ΔR |  |  | 10 | % | -20 °C / +25 °C / +125 °C / +25 °C, 10 cycles | 4 |

## CAD (KiCad official)

- Symbol: `SF-1206S125-2`
- Footprint: `Fuse:Fuse_1206_3216Metric`
- 3D model: 1206 (KiCad packages3D, STEP)
- 3D model files: `sf-1206s125-2-etched.step` / `sf-1206s125-2-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sf-1206s125-2.step` / `sf-1206s125-2.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [BOURNS datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603319479665373184) (5 pp, sha256 `703b1f579a261b6b`, 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/sf-1206s125-2-datasheet.pdf)