# 2N3904S-RTK

**KEC Semicon** · Bipolar (BJT) · SOT-23

2N3904S-RTK from KEC Semicon, in a SOT-23. 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 | EMITTER | passive | Emitter terminal of the NPN transistor; the absolute maximum emitter-base voltage VEBO is 6 V. |
| 2 | BASE | passive | Base terminal of the NPN transistor; the absolute maximum base current IB is 50 mA. |
| 3 | COLLECTOR | passive | Collector terminal of the NPN transistor; the absolute maximum collector-base voltage VCBO is 60 V, collector-emitter voltage VCEO is 40 V, and collector current IC is 200 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | KEC Semicon |
| Package | SOT-23 |
| Category | Transistors/Thyristors |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `2N3904S-RTK`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `2n3904s-rtk-etched.step` / `2n3904s-rtk-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `2n3904s-rtk.step` / `2n3904s-rtk.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [KEC Semicon datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8586173324804706304) (4 pp, sha256 `349bb72e391ed0e6`, retrieved 2026-10-09, 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/2n3904s-rtk-datasheet.pdf)