# FRM121WJR020TM

**FOJAN** · Current Sense Resistors / Shunt Resistors · 1206

FRM121WJR020TM from FOJAN, in a 1206. 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 | FOJAN |
| Package | 1206 |
| 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 (nominal, code R020) | R |  | 20 |  | mΩ | Part-number resistance code R020 = 20 mΩ (marking rule: R = decimal point, 'R001=1mΩ'); Kelvin four-terminal measurement | 2 |
| Resistance range (1206, 1 W row) |  | 1 |  | 100 | mΩ | Type 1206, power rating 1 W, 'Resistance Range (mΩ)' column | 5 |
| Tolerance (code J) |  | -5 |  | 5 | % | Part-number tolerance letter J = ±5% | 2 |
| Temperature coefficient of resistance (T.C.R.) | TCR | -50 |  | 50 | PPM/℃ | Type 1206, 1 W row; ±50 PPM/℃; measured at 25 ℃ and +125 ℃, reference +25 ℃ | 5 |
| Power rating at P70 | P70 |  |  | 1 | W | Type 1206, 1 W row, 'Power Rating at P70 (W)' | 5 |
| Rated current |  |  |  | 31 | A | Type 1206, 1 W row, 'Rated Current (A)' column | 5 |
| Max overload current |  |  |  | 70 | A | Type 1206, 1 W row, 'Max overload Current (A)' column | 5 |
| Operating temperature range |  | -55 |  | 170 | ℃ | Type 1206, 1 W row, 'Operating Temperature (°C)' -55℃ to 170℃ | 5 |
| Hand soldering temperature |  |  | 350 |  | ℃ | Iron temperature 350±10℃, hand soldering time less than 3 s; avoid iron tip touching resistor body | 9 |
| Resistance change, high temperature exposure (storage) | △R | -1 |  | 1 | % | T=170℃, 1000 h, measured 24 h after test | 6 |
| Resistance change, low temperature exposure (storage) | △R | -0.5 |  | 0.5 | % | T=-55℃, 1000 h, measured 24 h after test | 6 |
| Resistance change, temperature cycling | △R | -0.5 |  | 0.5 | % | 1000 cycles, -55℃ to 125℃, measured 24 h after test | 6 |
| Resistance change, short time overload | △R | -0.5 |  | 0.5 | % | 5 X rated power for 5 s | 6 |
| Resistance change, moisture resistance | △R | -1 |  | 1 | % | 24 h per cycle, 10 cycles, notes steps 7a & 7b not required | 6 |
| Resistance change, biased humidity | △R | -0.5 |  | 0.5 | % | 10% rated power, 85℃, RH 85%, 1000 h, measured 24 h after test | 6 |
| Resistance change, load life | △R | -1 |  | 1 | % | 1000 h at +70℃, 1.5 h ON / 0.5 h OFF, measured 24 h after test | 7 |
| Resistance change, resistance to soldering heat | △R | -0.5 |  | 0.5 | % | 260±5℃ solder, 10±1 s dwell | 7 |
| Resistance change, mechanical shock | △R | -0.5 |  | 0.5 | % | 100 g, 6 ms half sine pulse, 3 shocks in each of six directions | 7 |
| Resistance change, vibration | △R | -0.5 |  | 0.5 | % | 5 g, 10-2000 Hz, 20 min per cycle, 12 cycles in X, Y, Z | 7 |
| Resistance change, board flex | △R | -0.5 |  | 0.5 | % | Min 2 mm deflection, 60 s | 7 |
| Resistance change, thermal shock | △R | -1 |  | 1 | % | -55℃/+155℃, 1000 cycles | 7 |
| Resistance change, ESD | △R | -1 |  | 1 | % | Direct contact ±6 kV; air discharge +12 kV, +16 kV, +25 kV | 7 |

## CAD (KiCad official)

- Symbol: `FRM121WJR020TM`
- Footprint: `Resistor_SMD:R_1206_3216Metric`
- 3D model: 1206 (KiCad packages3D, STEP)
- 3D model files: `frm121wjr020tm-etched.step` / `frm121wjr020tm-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `frm121wjr020tm.step` / `frm121wjr020tm.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [FOJAN datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8763505047529906176) (12 pp, sha256 `13a1c74e6b23cc10`, retrieved 2026-10-17, tier: lcsc)
- **Datasheet language:** Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- **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/frm121wjr020tm-datasheet.pdf)