# MMBT3904-E

**MDD Microdiode Semiconductor** · Bipolar (BJT) · SOT-23

MMBT3904-E from MDD Microdiode Semiconductor, in a SOT-23. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | BASE | input | Base control terminal with maximum Emitter-Base voltage of 6V. |
| 2 | EMITTER | passive | Emitter terminal with maximum Emitter-Base voltage of 6V. |
| 3 | COLLECTOR | passive | Collector terminal with maximum Collector-Emitter voltage of 40V, collector current of 200mA, and power dissipation of 200mW. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | MDD Microdiode Semiconductor |
| Package | SOT-23 |
| Category | Transistors/Thyristors |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `MMBT3904-E`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `mmbt3904-e-etched.step` / `mmbt3904-e-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmbt3904-e.step` / `mmbt3904-e.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [MDD Microdiode Semiconductor datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8604434048337133568) (5 pp, sha256 `f58ab3457a23b7ce`, retrieved 2026-09-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.2`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-4-6` (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/mmbt3904-e-datasheet.pdf)