# MMST5551-JSM

**JSMSEMI** · Bipolar (BJT) · SOT-323

MMST5551-JSM from JSMSEMI, 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 | BASE | input | Base of the NPN transistor; emitter-base breakdown voltage is 6 V minimum (VEBO rating 6 V). |
| 2 | EMITTER | passive | Emitter of the NPN transistor; collector current is rated up to 600 mA. |
| 3 | COLLECTOR | passive | Collector of the NPN transistor; VCBO 180 V, VCEO 160 V, IC 600 mA, power dissipation 200 mW. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | JSMSEMI |
| Package | SOT-323 |
| Category | Transistors/Thyristors |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `MMST5551-JSM`
- Footprint: `Package_TO_SOT_SMD:SOT-323_SC-70`
- 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files: `mmst5551-jsm-etched.step` / `mmst5551-jsm-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmst5551-jsm.step` / `mmst5551-jsm.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [JSMSEMI datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603406431282745344) (3 pp, sha256 `586004260722ddac`, retrieved 2026-10-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (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/mmst5551-jsm-datasheet.pdf)