# ESDL031-1BF4

**STMicroelectronics** · ESD And Surge Protection (TVS/ESD) · 0201

ESDL031-1BF4 from STMicroelectronics, in a 0201. 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 | Bidirectional TVS terminal 1 (marked pin 1 side), line protected against ESD with VRM 3.3 V, VBR 5.0 to 6.6 V at 1 mA; terminals are interchangeable in polarity. |
| 2 | 2 | passive | Bidirectional TVS terminal 2, the opposite terminal to pin 1; the device clamps to 6.3 V TLP at 16 A and has 10 to 12 pF line capacitance. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | 0201 |
| Category | Circuit Protection |
| Pins | 2 |

## CAD (KiCad official)

- Symbol: `ESDL031-1BF4`
- Footprint: `Diode_SMD:D_0201_0603Metric`
- 3D model: 0201, generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 0.3 mm nominal _01005_ height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)

## Provenance

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

- **Datasheet:** [STMicroelectronics datasheet](https://www.st.com/resource/en/datasheet/esdl031-1bf4.pdf) (11 pp, sha256 `1f535f7fa3359c70`, retrieved 2026-10-08, tier: manufacturer)
- **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/esdl031-1bf4-datasheet.pdf)