# K121002

**KUU** · Disposable Fuses · 1206

K121002 from KUU, 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 | Fuse terminal 1 (unpolarized); part is rated 2A, with rated voltage of 72V/63V/32V/24V DC and 103-165 mOhm typical cold resistance. |
| 2 | 2 | passive | Fuse terminal 2 (unpolarized); part is rated 2A, with rated voltage of 72V/63V/32V/24V DC and 103-165 mOhm typical cold resistance. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | KUU |
| 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 |
|---|---|---|---|---|---|---|---|
| Operating temperature |  | -55 |  | 125 | °C | Operating temperature, with proper correction factor applied (temperature derating curve) | 3 |
| Storage temperature |  |  |  | 40 | °C | Packed in original packaging | 4 |
| Storage relative humidity |  |  |  | 70 | % RH | Packed in original packaging | 4 |
| Typical cold resistance |  | 103 |  | 165 | mOhms | DC cold resistance measured at <10% of rated current, ambient 25℃ | 1 |
| Time to open at 1.0In |  | 4 |  |  | hour | Rated current 250mA~5A, 1.0In | 1 |
| Time to open at 2.5In |  |  |  | 5 | sec | Rated current 250mA~5A, 2.5In | 1 |
| Wave solder time in reservoir |  |  |  | 10 | sec | Wave solder, reservoir temperature 260℃ | 2 |
| Infrared reflow time |  |  |  | 30 | sec | Infrared reflow, temperature 260℃ | 2 |
| Preheat and soak temperature Tsmin | Tsmin | 150 |  |  | ℃ | Lead(Pb) free solder reflow profile | 3 |
| Preheat and soak temperature Tsmax | Tsmax |  |  | 200 | ℃ | Lead(Pb) free solder reflow profile | 3 |
| Preheat and soak time Tsmin to Tsmax | tS | 60 |  | 120 | Seconds | Lead(Pb) free solder reflow profile | 3 |
| Average ramp up rate Tsmax to Tp |  |  |  | 3 | ℃ / Second | Lead(Pb) free solder reflow profile | 3 |
| Time at liquidous | tL | 60 |  | 150 | Seconds | Lead(Pb) free solder reflow profile, liquidous temperature TL 217℃ | 3 |
| Average ramp-down rate TP to Tsmax |  |  |  | 6 | ℃ / Second | Lead(Pb) free solder reflow profile | 3 |
| Time from 25℃ to peak temperature |  |  |  | 8 | Minutes | Lead(Pb) free solder reflow profile | 3 |
| Rated current |  |  | 2 |  | A | Part No. K121002 rated current column | 1 |

## CAD (KiCad official)

- Symbol: `K121002`
- Footprint: `Fuse:Fuse_1206_3216Metric`
- 3D model: 1206 (KiCad packages3D, STEP)
- 3D model files: `k121002-etched.step` / `k121002-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `k121002.step` / `k121002.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [KUU datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590191852784947200) (4 pp, sha256 `fc8f76d94ef04f38`, retrieved 2026-10-17, 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/k121002-datasheet.pdf)