# ESD56181W12-2

**WILLSEMI Will Semicon** · ESD And Surge Protection (TVS/ESD) · SOD-323

ESD56181W12-2 from WILLSEMI Will Semicon, in a SOD-323. 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 | Pin1 | passive | Pin 1 is one of the two terminals of this uni-directional TVS, and the datasheet measures the device's voltage parameters from pin 1 to pin 2 but does not state its individual function. |
| 2 | Pin2 | passive | Pin 2 is the second terminal of this uni-directional TVS, and the datasheet measures the device's voltage parameters from pin 1 to pin 2 but does not state its individual function. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | WILLSEMI Will Semicon |
| Package | SOD-323 |
| 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 |
|---|---|---|---|---|---|---|---|
| Reverse stand-off voltage | VRWM |  |  | 12 | V |  | 3 |
| Breakdown voltage | VBR | 12.8 | 13.6 | 14.5 | V | IBR = 1mA | 3 |
| Reverse leakage current | IRM |  |  | 0.1 | μA | at VRWM | 3 |
| Forward voltage | VF | 0.6 |  | 1.1 | V | IF = 20mA | 3 |
| Junction capacitance |  |  | 425 | 500 | pF | F = 1MHz, VR=0V | 3 |
| Rated peak pulse current | IPP |  |  | 75 | A | 8/20μs waveform per IEC61000-4-5 (notes 1, 2) | 3 |
| Clamping voltage | VCL |  | 21.5 | 24 | V | at IPP; notes 1) 2) | 3 |
| Peak pulse power | Ppk |  |  | 1800 | W | tp = 8/20μs | 2 |
| ESD protection (air discharge, IEC61000-4-2) | VESD | -30 |  | 30 | kV | IEC61000-4-2 air discharge | 2 |
| ESD protection (contact discharge, IEC61000-4-2) | VESD | -30 |  | 30 | kV | IEC61000-4-2 contact discharge | 2 |
| Junction temperature | TJ |  |  | 125 | °C |  | 2 |
| Operating temperature | TOP | -40 |  | 85 | °C |  | 2 |
| Lead temperature | TL |  |  | 260 | °C |  | 2 |
| Storage temperature | TSTG | -55 |  | 150 | °C |  | 2 |

## CAD (KiCad official)

- Symbol: `ESD56181W12-2`
- Footprint: `Diode_SMD:D_SOD-323`
- 3D model: SOD-323 (KiCad packages3D, STEP)
- 3D model files: `esd56181w12-2-etched.step` / `esd56181w12-2-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `esd56181w12-2.step` / `esd56181w12-2.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [WILLSEMI Will Semicon datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590208224181063680) (6 pp, sha256 `ab0dcfd2f150c0fb`, retrieved 2026-10-22, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-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/esd56181w12-2-datasheet.pdf)