# BC857BS

**FUXINSEMI** · Bipolar (BJT) · SOT-363

BC857BS from FUXINSEMI, in a SOT-363. 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 | E1 | passive | Emitter of transistor 1 (PNP); emitter-base voltage limit -5 V, continuous collector current -0.2 A per the maximum ratings. |
| 2 | B1 | passive | Base of transistor 1 (PNP); VCE(sat) max -0.3 V at IC=-10 mA, IB=-0.5 mA. |
| 3 | C2 | passive | Collector of transistor 2 (PNP); collector-emitter voltage limit -45 V and collector-base voltage limit -50 V. |
| 4 | E2 | passive | Emitter of transistor 2 (PNP); emitter-base voltage limit -5 V. |
| 5 | B2 | passive | Base of transistor 2 (PNP); hFE 250-475 for the BC857BS rank at VCE=-5 V, IC=-2 mA. |
| 6 | C1 | passive | Collector of transistor 1 (PNP); collector-emitter voltage limit -45 V and collector-base voltage limit -50 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | FUXINSEMI |
| Package | SOT-363 |
| Category | Transistors/Thyristors |
| Pins | 6 |

## CAD (KiCad official)

- Symbol: `BC857BS`
- Footprint: `Package_TO_SOT_SMD:SOT-363_SC-70-6`
- 3D model: SOT-363 (KiCad packages3D, STEP)
- 3D model files: `bc857bs-etched.step` / `bc857bs-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc857bs.step` / `bc857bs.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [FUXINSEMI datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590908595498266624) (3 pp, sha256 `7a58bf4848642643`, retrieved 2026-10-09, 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/bc857bs-datasheet.pdf)