# 0438001.WRA

**Littelfuse** · Disposable Fuses · 0603

0438001.WRA from Littelfuse, in a 0603. 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 | One of two interchangeable end terminations (Ag/Ni/Sn) of the non-polarized 1 A fast-acting fuse, rated 63VDC with 50A @ 63VDC / 32VAC interrupting rating. |
| 2 | 2 | passive | Second interchangeable end termination (Ag/Ni/Sn) of the non-polarized 1 A fast-acting fuse; the series operates from -55ºC to +150ºC. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Littelfuse |
| Package | 0603 |
| 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 |
|---|---|---|---|---|---|---|---|
| Maximum voltage rating |  |  |  | 63 | V | DC, 1A (amp code 001.) | 1 |
| Interrupting rating (DC) |  |  |  | 50 | A | at 63VDC, time constant < 0.8 msec | 1 |
| Interrupting rating (AC) |  |  |  | 50 | A | at 32VAC, unity power factor | 1 |
| Opening time at 100% of ampere rating |  | 4 |  |  | hours | at 25°C, 100% of ampere rating (minimum) | 1 |
| Opening time at 250% of ampere rating |  |  |  | 5 | s | at 25°C, 250% of ampere rating (maximum) | 1 |
| Operating temperature |  | -55 |  | 150 | °C |  | 1 |
| Continuous operating current |  |  |  | 80 | % of rated current | devices operated continuously; standard 20% re-rating for continuous operation also applies | 2 |
| Wave soldering temperature |  |  |  | 260 | °C | wave soldering, 10 seconds max | 2 |
| Nominal resistance |  |  | 0.31 |  | Ω | measured with < 10% rated current | 1 |
| Nominal melting I2t | I2t |  | 0.0593 |  | A2Sec. | measured at 1 msec. opening time | 1 |
| Nominal voltage drop at rated current |  |  | 0.351 |  | V | measured at rated current after temperature has stabilized | 1 |
| Nominal power dissipation at rated current |  |  | 0.351 |  | W | at rated current | 1 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts |  | tin | Terminations: Ag/Ni/Sn (100% Lead-free) Element Cover Coating: Lead-free Glass | 3 |

## CAD (KiCad official)

- Symbol: `0438001.WRA`
- Footprint: `Fuse:Fuse_0603_1608Metric`
- 3D model: 0603 (KiCad packages3D, STEP)
- 3D model files: `0438001-wra-etched.step` / `0438001-wra-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `0438001-wra.step` / `0438001-wra.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Littelfuse datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590905752637304832) (4 pp, sha256 `e39993e942f8fa16`, 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/0438001-wra-datasheet.pdf)