# 0603L025YR

**Littelfuse** · Resettable Fuses · 0603

0603L025YR 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, non-polarized solder-plated copper terminals of the 0603L025 PTC (Ihold 0.25 A, Itrip 0.55 A, Vmax 9 Vdc, Imax 40 A). |
| 2 | 2 | passive | Second interchangeable, non-polarized solder-plated copper terminal of the 0603L025 PTC, in series with the protected circuit (Ihold 0.25 A, Vmax 9 Vdc). |

## 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 |
|---|---|---|---|---|---|---|---|
| Minimum resistance (initial, un-soldered) | R min | 0.5 |  |  | Ω | Initial (un-soldered) state | 1 |
| Maximum resistance at 20°C after trip or reflow | R1max |  |  | 3 | Ω | 20°C, measured one hour after tripping or reflow soldering at 260°C for 20 sec | 1 |
| Hold current | I hold |  |  | 0.25 | A | 20°C still air; maximum current device will pass without tripping | 1 |
| Trip current | I trip | 0.55 |  |  | A | 20°C still air; minimum current at which the device will trip | 1 |
| Maximum voltage | V max |  |  | 9 | Vdc | At rated current (I max) | 1 |
| Maximum fault current | I max |  |  | 40 | A | At rated voltage (Vmax) | 1 |
| Power dissipated in tripped state | P d |  | 0.5 |  | W | Tripped state, 20°C still air | 1 |
| Maximum time to trip |  |  |  | 0.08 | s | At 8.00 A | 1 |
| Operating/storage temperature |  | -40 |  | 85 | °C | Operating/storage | 3 |
| Maximum device surface temperature in tripped state |  |  |  | 125 | °C | Tripped state | 3 |
| Passive aging resistance change |  | -10 |  | 10 | % | +85°C, 1000 hours; typical resistance change | 3 |
| Humidity aging resistance change |  | -15 |  | 15 | % | +85°C, 85% R.H., 100 hours; typical resistance change | 3 |
| Thermal shock resistance change |  |  | -30 |  | % | MIL-STD-202 Method 107, +85°C/-40°C 20 times; typical resistance change | 3 |
| Peak classification temperature (reflow) | TP |  |  | 260 | °C | Pb-free reflow profile; printed tolerance +0/-5 °C | 3 |

## 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 | Copper |  | Terminal Material Solder-Plated Copper | 3 |

## CAD (KiCad official)

- Symbol: `0603L025YR`
- Footprint: `Fuse:Fuse_0603_1608Metric`
- 3D model: 0603 (KiCad packages3D, STEP)
- 3D model files: `0603l025yr-etched.step` / `0603l025yr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `0603l025yr.step` / `0603l025yr.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/8588906601419837440) (5 pp, sha256 `64bb6c9d39cb226b`, retrieved 2026-10-16, 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/0603l025yr-datasheet.pdf)