# LR122WF650MT4E

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

LR122WF650MT4E 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 |  | -1 |  | 1 | % | F = ±1% (7th code) | 2 |
| Temperature coefficient of resistance | TCR | -50 |  | 50 | ppm/°C | R1 at +25°C, R2 at 125°C; TCR = (R2-R1)/(R1(t2-t1)) x 10^6 | 4 |
| Rated power | P |  |  | 2 | W | Continuous load at 70°C ambient; derated above 70°C per Figure 1 | 4 |
| Short-time overload resistance change | ΔR | -0.5 |  | 0.5 | % | 5 times rated power for 5 s (LR12-2W) | 4 |
| Load life resistance change | ΔR | -1 |  | 1 | % | 1000 h at rated power or max working current, 1.5 h on / 0.5 h off, 70±2°C ambient | 4 |
| High temperature exposure resistance change | ΔR | -1 |  | 1 | % | 155±2°C for 1000 h (MIL-STD-202 108A) | 4 |
| Biased humidity resistance change | ΔR | -0.5 |  | 0.5 | % | 85°C/85%RH, 1000 h, 10% of operating power; measured 24±4 h after test | 4 |
| Rapid change of temperature resistance change | ΔR | -0.5 |  | 0.5 | % | 30 min at -55°C and 30 min at 155°C; 100 cycles | 4 |
| Terminal bending resistance change | ΔR | -0.5 |  | 0.5 | % | 2 mm, 10 s | 4 |
| Resistance to solder heat resistance change | ΔR | -0.5 |  | 0.5 | % | 260±5°C, held 10±1 s | 4 |
| Solderability wetted coverage |  | 95 |  |  | % | Solder 245±3°C; dwell 2~3 s; coverage >95% | 4 |
| Storage temperature |  | 15 |  | 35 | °C | Warehouse storage, manufacturer recommendation | 6 |
| Storage relative humidity |  | 25 |  | 75 | %RH | Warehouse storage, manufacturer recommendation | 6 |
| Reflow peak temperature | Tp |  |  | 260 | °C | Pb-free reflow, within +0/-5°C of peak for 10 s; 2 reflow cycles max | 5 |

## CAD (KiCad official)

- Symbol: `LR122WF650MT4E`
- Footprint: `Resistor_SMD:R_2512_6332Metric`
- 3D model: 2512 (KiCad packages3D, STEP)
- 3D model files: `lr122wf650mt4e-etched.step` / `lr122wf650mt4e-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lr122wf650mt4e.step` / `lr122wf650mt4e.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/8590921997809360896) (6 pp, sha256 `697e24f2047069dc`, retrieved 2026-11-05, 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/lr122wf650mt4e-datasheet.pdf)