# BAS20W

**ST Semtech** · Switching Diodes · SOT-323

BAS20W from ST Semtech, in a SOT-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 | A | passive | Anode of the single diode (BAS19W/BAS20W/BAS21W share this pinout); BAS20W is rated for 200 V reverse voltage and 200 mA continuous forward current. |
| 2 | NC | unconnected | Not connected internally on the single-diode BAS20W; no diode terminal is drawn at pin 2 in the package diagram. |
| 3 | K | passive | Cathode of the single diode; BAS20W reverse breakdown is 200 V minimum at IR = 100 µA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ST Semtech |
| Package | SOT-323 |
| Category | Diodes |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `BAS20W`
- Footprint: `Package_TO_SOT_SMD:SOT-323_SC-70`
- 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files: `bas20w-etched.step` / `bas20w-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bas20w.step` / `bas20w.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [ST Semtech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603160562017202176) (4 pp, sha256 `63c87ed3a90e2cce`, retrieved 2026-10-09, 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/bas20w-datasheet.pdf)