# MMBT5401L

**Changjing** · Bipolar Transistors - BJT · SOT-23

MMBT5401L from Changjing, 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 | BASE | input | Base terminal; the emitter-base voltage VEBO is limited to -5 V and the base drives the device with IB=-1mA to -5mA in the stated saturation tests. |
| 2 | EMITTER | passive | Emitter terminal; the emitter-base breakdown voltage V(BR)EBO is -5 V minimum at IE=-10µA. |
| 3 | COLLECTOR | passive | Collector terminal; rated for VCBO of -160 V, VCEO of -150 V and collector current IC of -0.6 A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-23 |
| Category | Triode/MOS Tube/Transistor |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `MMBT5401L`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `mmbt5401l-etched.step` / `mmbt5401l-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmbt5401l.step` / `mmbt5401l.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Changjing datasheet](docs/mmbt5401l-datasheet.pdf) (4 pp, sha256 `951d004056e9f8af`, retrieved 2026-10-28, 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/mmbt5401l-datasheet.pdf)