# BC857BW

**HUXN** · Bipolar (BJT) · SOT-323

BC857BW from HUXN, 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 | passive | Base terminal of the BC857BW PNP transistor; the datasheet gives an emitter-base breakdown voltage VEBO of -5 V and a continuous collector current IC of -0.1 A. |
| 2 | EMITTER | passive | Emitter terminal of the BC857BW PNP transistor; the emitter-base rating is VEBO = -5 V. |
| 3 | COLLECTOR | passive | Collector terminal of the BC857BW PNP transistor; for the BC857W the maximum ratings are VCBO = -50 V and VCEO = -45 V, with collector power dissipation PC of 150 mW. |

## Key specifications

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

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Collector-base breakdown voltage (BC857W) | VCBO | -50 |  |  | V | IC= -10μA, IE=0 | 2 |
| Collector-emitter breakdown voltage (BC857W) | VCEO | -45 |  |  | V | IC= -10mA, IB=0 | 2 |
| Emitter-base breakdown voltage | VEBO | -5 |  |  | V | IE= -1μA, IC=0 | 2 |
| DC current gain (BC857BW, 857BW group) | hFE | 220 |  | 475 |  | VCE= -5V, IC= -2mA | 2 |
| Collector cut-off current | ICBO |  |  | -15 | nA | VCB= -30 V , IE=0 | 2 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -0.65 | V | IC=-100mA, IB= -5mA | 2 |
| Base-emitter saturation voltage | VBE(sat) |  |  | -1.1 | V | IC= -100mA, IB= -5mA | 2 |
| Transition frequency | fT | 100 |  |  | MHz | VCE= -5V, IC= -10mA, f=100MHz | 2 |
| Collector capacitance | Cob |  |  | 4.5 | pF | VCB=-10V, f=1MHz | 2 |
| Collector-base voltage (BC857W) | VCBO |  |  | -50 | V |  | 1 |
| Collector-emitter voltage (BC857W) | VCEO |  |  | -45 | V |  | 1 |
| Emitter-base voltage | VEBO |  |  | -5 | V |  | 1 |
| Collector current, continuous | IC |  |  | -0.1 | A |  | 1 |
| Collector power dissipation | PC |  |  | 150 | mW |  | 1 |
| Junction temperature | TJ |  |  | 150 | ℃ |  | 1 |
| Storage temperature | Tstg | -65 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `BC857BW`
- Footprint: `Package_TO_SOT_SMD:SOT-323_SC-70`
- 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files: `bc857bw-etched.step` / `bc857bw-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc857bw.step` / `bc857bw.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [HUXN datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590261238069424128) (4 pp, sha256 `a217278754e52932`, retrieved 2026-10-17, 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/bc857bw-datasheet.pdf)