# LR122WF150LT4E

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

LR122WF150LT4E 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 | First terminal of the LR12 (2512) metal strip chip resistor, a Sn-plated end electrode (A = 0.90±0.25 mm or 0.65±0.25 mm depending on rating and resistance range) for the 3~350mΩ element. |
| 2 | 2 | passive | Second terminal of the LR12 (2512) metal strip chip resistor, a Sn-plated end electrode interchangeable with the first, rated 1.5W (LR122W-class 2W/3W series per part code, 1A=1.5W) at 70°C with derating above 70°C. |

## 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 (part-number code F) |  | -1 |  | 1 | % | MPN 7th code F = ±1% | 2 |
| Temperature coefficient of resistance |  | -50 |  | 50 | ppm/°C | t1 +25°C, t2 125°C test temperature | 4 |
| Resistance range, LR12 (2512) 2W | R | 26 |  | 350 | mΩ | LR12 2W, 26~350mΩ group | 3 |
| Nominal resistance (decoded from MPN codes 8-11) | R |  | 0.15 |  | Ω | MPN digits 150 with 11th code L = 10^-3 | 2 |
| Rated power | P |  |  | 2 | W | Continuous load at ambient 70°C; derate above 70°C per Figure 1 | 3 |
| Short-time overload ΔR | ΔR | -0.5 |  | 0.5 | % | 5 times rated power for 5 s (LR12-2W) | 4 |
| Short-time overload ΔR additive term | ΔR | -0.0005 |  | 0.0005 | Ω | 5 times rated power for 5 s (LR12-2W) | 4 |
| Load life ΔR | ΔR | -1 |  | 1 | % | 1000 h at 70±2°C, rated or max working current (lesser), 1.5 h ON / 0.5 h OFF | 4 |
| Load life ΔR additive term | ΔR | -0.0005 |  | 0.0005 | Ω | 1000 h at 70±2°C, rated or max working current (lesser), 1.5 h ON / 0.5 h OFF | 4 |
| High temperature exposure ΔR | ΔR | -1 |  | 1 | % | MIL-STD-202 108A, 155±2°C, 1000 h | 4 |
| High temperature exposure ΔR additive term | ΔR | -0.0005 |  | 0.0005 | Ω | MIL-STD-202 108A, 155±2°C, 1000 h | 4 |
| Biased humidity ΔR | ΔR | -0.5 |  | 0.5 | % | MIL-STD-202 Method 103, 85°C/85%RH, 1000 h, 10% of operating power | 4 |
| Biased humidity ΔR additive term | ΔR | -0.0005 |  | 0.0005 | Ω | MIL-STD-202 Method 103, 85°C/85%RH, 1000 h, 10% of operating power | 4 |
| Rapid change of temperature ΔR | ΔR | -0.5 |  | 0.5 | % | 30 min at -55°C and 30 min at 155°C; 100 cycles | 4 |
| Rapid change of temperature ΔR additive term | ΔR | -0.0005 |  | 0.0005 | Ω | 30 min at -55°C and 30 min at 155°C; 100 cycles | 4 |
| Terminal bending ΔR | ΔR | -0.5 |  | 0.5 | % | 2 mm, 10 s | 4 |
| Terminal bending ΔR additive term | ΔR | -0.0005 |  | 0.0005 | Ω | 2 mm, 10 s | 4 |
| Resistance to solder heat ΔR | ΔR | -0.5 |  | 0.5 | % | 260±5°C, held 10±1 s | 4 |
| Resistance to solder heat ΔR additive term | ΔR | -0.0005 |  | 0.0005 | Ω | 260±5°C, held 10±1 s | 4 |
| Solderability terminal coverage |  | 95 |  |  | % | Solder temperature 245±3°C, dwell 2~3 s | 4 |
| Dielectric withstanding test current limit |  |  |  | 50 | mA | Applied 500 VAC for 1 min; limit surge current | 4 |
| Preheat temperature |  | 150 |  | 200 | °C | Pb-free reflow, Tsmin to Tsmax | 5 |
| Preheat time | ts | 60 |  | 120 | s | Pb-free reflow, Tsmin to Tsmax | 5 |
| Average ramp-up rate |  |  |  | 3 | °C/s | Ts max to Tp | 5 |
| Time maintained above TL | tL | 60 |  | 150 | s | TL = 217°C | 5 |
| Liquidus temperature TL | TL |  | 217 |  | °C | Time maintained above TL | 5 |
| Peak temperature | Tp |  |  | 260 | °C | Pb-free solder Sn96.5/Ag3/Cu0.5 | 5 |
| Time within +0/-5°C of actual peak temperature | tp |  | 10 |  | s | Within +0/-5°C of actual peak temperature | 5 |
| Ramp-down rate |  |  |  | 6 | °C/s | From peak temperature | 5 |
| Time 25°C to peak temperature |  |  |  | 8 | min | 25°C to peak temperature | 5 |
| Allowed reflow times |  |  |  | 2 | times | Reflow soldering | 5 |
| Recommended storage temperature |  | 15 |  | 35 | °C | Recommended warehouse storage (storage, not operating) | 7 |
| Recommended storage humidity |  | 25 |  | 75 | %RH | Recommended warehouse storage (storage, not operating) | 7 |

## CAD (KiCad official)

- Symbol: `LR122WF150LT4E`
- Footprint: `Resistor_SMD:R_2512_6332Metric`
- 3D model: 2512 (KiCad packages3D, STEP)
- 3D model files: `lr122wf150lt4e-etched.step` / `lr122wf150lt4e-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `lr122wf150lt4e.step` / `lr122wf150lt4e.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/8603144027294212096) (7 pp, sha256 `e01cdf7929676065`, retrieved 2026-10-21, 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/lr122wf150lt4e-datasheet.pdf)