# LR122WF280MT4E

**UNI ROYAL Uniroyal Elec** · Current Sense Resistors / Shunt Resistors · 2512

LR122WF280MT4E from UNI ROYAL Uniroyal Elec, in a 2512. 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 resistor; either orientation. |
| 2 | 2 | passive | Terminal 2 of an unpolarised resistor; either orientation. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | UNI ROYAL Uniroyal Elec |
| Package | 2512 |
| Category | Resistors |
| 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 |
|---|---|---|---|---|---|---|---|
| Resistance tolerance (F code = ±1%) |  | -1 |  | 1 | % | Part code 7th digit F = ±1% | 2 |
| Temperature coefficient (TCR) | TCR | -50 |  | 50 | ppm/℃ | LR12 2W ≦±50 row; R1 at room temp, R2 at room temp +100℃ (JIS C 5201-1 4.8) | 3 |
| Rated power at 70℃ | P |  |  | 2 | W | Power rating at 70℃ ambient; derate above 70℃ per Figure 1 (no numeric derating given) | 3 |
| Max rating current |  |  |  | 44.72 | A | LR12 2W ≦±50 row, resistance range 16~450 mΩ | 3 |
| Max overload current |  |  |  | 100 | A | LR12 2W ≦±50 row, resistance range 16~450 mΩ | 3 |
| Operating temperature range | T | -55 |  | 170 | ℃ | Printed as -55~+170℃ for LR series | 3 |
| Nominal resistance | R |  | 28 |  | mΩ | Decoded from MPN code 280M: 280 × 10^-4 Ω = 28 mΩ | 2 |
| Short-time overload resistance change | ΔR | -0.5 |  | 0.5 | % | Potential of 5 times power rate applied for 5 seconds | 6 |
| Operational life resistance change | ΔR | -1 |  | 1 | % | 1000 h at rated or max working current (whichever less), 1.5 h ON / 0.5 h OFF, 70±2℃ ambient | 6 |
| High temperature exposure resistance change | ΔR | -1 |  | 1 | % | Exposed to 170±2℃ for 1000 h (MIL-STD-202 108A) | 6 |
| Biased humidity resistance change | ΔR | -0.5 |  | 0.5 | % | 1000 h at 85℃/85%RH, 10% of operating power; measured 24±4 h after test | 6 |
| Rapid temperature change resistance change | ΔR | -0.5 |  | 0.5 | % | 30 min at -55℃ and 30 min at 170℃; 100 cycles | 6 |
| Terminal bending resistance change | ΔR | -0.5 |  | 0.5 | % | 2 mm, 60 s | 6 |
| Resistance to solder heat resistance change | ΔR | -0.5 |  | 0.5 | % | Dip in 260±5℃ for 10±1 s | 6 |

## CAD (KiCad official)

- Symbol: `LR122WF280MT4E`
- Footprint: `Resistor_SMD:R_2512_6332Metric`
- 3D model: 2512 (KiCad packages3D, STEP)
- 3D model files: `lr122wf280mt4e-etched.step` / `lr122wf280mt4e-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lr122wf280mt4e.step` / `lr122wf280mt4e.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [UNI ROYAL Uniroyal Elec datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603221940152774656) (8 pp, sha256 `9cafe18fe2eb29b6`, retrieved 2026-10-17, 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/lr122wf280mt4e-datasheet.pdf)