# RL1210A431K

**RUILON Shenzhen Ruilongyuan Elec** · Varistors · 1210

RL1210A431K from RUILON Shenzhen Ruilongyuan Elec, in a 1210. 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 end-termination of the bidirectional, symmetrical varistor; RL1210A431K is rated 275 VAC / 350 VDC max allowable voltage, with 387~473 V varistor voltage at 1 mA. |
| 2 | 2 | passive | Second end-termination of the bidirectional, symmetrical varistor, interchangeable with the first; clamping voltage is 710 V at 8/20μs and 5 A, and withstanding surge current is 250 A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | RUILON Shenzhen Ruilongyuan Elec |
| Package | 1210 |
| 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 |
|---|---|---|---|---|---|---|---|
| Varistor voltage | V1mA | 387 |  | 473 | V | V1mA, 1 mA test current; RL1210A431K row | 2 |
| Varistor voltage tolerance (K suffix) |  | -10 |  | 10 | % | K: ±10% | 1 |
| Max allowable voltage (AC) | VAC |  |  | 275 | V | RL1210A431K row | 2 |
| Max allowable voltage (DC) | VDC |  |  | 350 | V | RL1210A431K row | 2 |
| Max energy |  |  |  | 0.8 | J | 10/1000 μs | 2 |
| Max clamping voltage | VC |  |  | 710 | V | 8/20 μs | 2 |
| Withstanding surge current | I |  |  | 250 | A | 8/20 μs | 2 |
| Operating temperature range |  | -55 |  | 125 | °C |  | 1 |
| Storage temperature |  | 5 |  | 40 | °C | Storage condition | 2 |
| Storage relative humidity |  |  |  | 65 | %RH | Storage condition | 2 |
| Storage time |  |  |  | 12 | months | Taping package storage condition | 2 |
| Response time |  |  |  | 1 | ns | <1 ns | 2 |
| Varistor voltage change, bias humidity |  | -10 |  | 10 | % | 90%RH, 40ºC, working voltage, 1000 hrs | 2 |
| Varistor voltage change, thermal shock |  | -10 |  | 10 | % | -40ºC to 85ºC, 30 min cycle, 5 cycles | 2 |
| Varistor voltage change, full load |  | -10 |  | 10 | % | Working voltage, 85ºC, 1000 hrs | 2 |
| Solderability dip temperature |  | 240 |  | 250 | °C | 245±5 ºC, 3±1 sec | 2 |
| Soldering gun tip temperature |  |  |  | 280 | °C | Soldering gun under 30 W | 3 |
| Heat shock during soldering |  |  |  | 100 | °C | Do not give heat shock over 100°C in the process of soldering | 3 |

## CAD (KiCad official)

- Symbol: `RL1210A431K`
- Footprint: `Resistor_SMD:R_1210_3225Metric`
- 3D model: 1210 (KiCad packages3D, STEP)
- 3D model files: `rl1210a431k-etched.step` / `rl1210a431k-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `rl1210a431k.step` / `rl1210a431k.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [RUILON Shenzhen Ruilongyuan Elec datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590226931762159616) (4 pp, sha256 `e8cd1faffba96262`, retrieved 2026-10-17, 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/rl1210a431k-datasheet.pdf)