# 1206TD-4A

**prosemi** · Disposable Fuses · 1206

1206TD-4A from prosemi, 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 (interchangeable with terminal 2); 4.00 A rated time-delay element with 0.033 ohm typical cold resistance and 0.175 V typical drop at rated current. |
| 2 | 2 | passive | Fuse terminal 2 (interchangeable with terminal 1); 4.00 A rated time-delay element, one-time positive disconnect, operating temperature -55 to 125°C. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | prosemi |
| 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 |
|---|---|---|---|---|---|---|---|
| Opening time at 100% of amp rating (0.75~30A) |  | 4 |  |  | Hours | 100% of amp rating, 0.75~30A | 1 |
| Opening time at 250% of amp rating (0.75~5A) |  |  |  | 5 | Seconds | 250% of amp rating, 0.75~5A | 1 |
| Opening time at 300% of amp rating (0.75~5A) |  | 0.1 |  | 3 | sec | 300% of amp rating, 0.75~5A | 1 |
| Opening time at 1000% of amp rating (0.75~30A) |  | 0.2 |  | 20 | ms | 1000% of amp rating, 0.75~30A | 1 |
| Operating temperature |  | -55 |  | 125 | °C | Operating temperature | 2 |
| Wave soldering temperature |  |  |  | 260 | °C | Wave soldering, 10 seconds max. | 2 |
| Infrared reflow temperature |  |  |  | 260 | °C | Infrared reflow, 30 seconds max. | 2 |
| Average ramp-up rate (Tsmax to Tp) |  |  |  | 3 | °C/second | Average ramp-up rate, Tsmax to Tp | 2 |
| Average ramp-down rate (Tp to Tsmax) |  |  |  | 6 | °C/second | Average ramp-down rate, Tp to Tsmax | 2 |
| Preheat temperature (Tsmin to Tsmax) |  | 150 |  | 200 | °C | Preheat, time Tsmin to Tsmax 60-120 seconds | 2 |
| Ampere rating |  |  | 4 |  | A | Nominal rated current for 1206TD-4A | 1 |
| Typical cold resistance |  |  | 0.033 |  | Ohms | DC cold resistance, measured at <10% of rated current in ambient 25°C | 1 |
| Typical melting I2t |  |  | 3.1 |  | A Sec | Measured at 10In current | 1 |
| Typical voltage drop |  |  | 0.175 |  | V | Measured at rated current after temperature has stabilized | 1 |

## CAD (KiCad official)

- Symbol: `1206TD-4A`
- Footprint: `Fuse:Fuse_1206_3216Metric`
- 3D model: 1206 (KiCad packages3D, STEP)
- 3D model files: `1206td-4a-etched.step` / `1206td-4a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `1206td-4a.step` / `1206td-4a.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/8590229301603180544) (3 pp, sha256 `417cc80078d635cf`, 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/1206td-4a-datasheet.pdf)