# KN4401S-RTK

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

KN4401S-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 emitter-base voltage is limited to 6 V (VEBO) and the collector current to 600 mA. |
| 2 | BASE | passive | Base terminal of the NPN transistor; base-emitter voltage is specified with VBE(sat) of 0.75 to 0.95 V at IC=150 mA, IB=15 mA and up to 1.2 V at IC=500 mA, IB=50 mA. |
| 3 | COLLECTOR | passive | Collector terminal of the NPN transistor; the collector-emitter voltage is limited to 40 V (VCEO) and the collector power dissipation to 350 mW. |

## Key specifications

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

## CAD (KiCad official)

- Symbol: `KN4401S-RTK`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `kn4401s-rtk-etched.step` / `kn4401s-rtk-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `kn4401s-rtk.step` / `kn4401s-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/8588884490608889856) (3 pp, sha256 `c79eb053b02a8348`, 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/kn4401s-rtk-datasheet.pdf)