# BC858CW

**Yangzhou Yangjie Elec Tech** · Bipolar (BJT) · SOT-323

BC858CW from Yangzhou Yangjie Elec Tech, 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 | B | input | Base of the PNP transistor; the datasheet gives a collector-base breakdown of -30 V and an emitter-base maximum of -6 V for BC858CW. |
| 2 | E | passive | Emitter of the PNP transistor; the emitter-base voltage is rated at -6 V maximum. |
| 3 | C | passive | Collector of the PNP transistor; the datasheet gives -30 V collector-emitter voltage (BC858CW) and -0.1 A continuous current. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Yangzhou Yangjie Elec Tech |
| 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 (BC858) | BVCBO | -30 |  |  | V | IC= -10µA, IE=0 | 2 |
| Collector-emitter breakdown voltage (BC858) | BVCEO | -30 |  |  | V | IC= -10mA, IB=0 | 2 |
| Emitter-base breakdown voltage | BVEBO | -5 |  |  | V | IE= -1µA, IC=0 | 2 |
| Collector cut-off current | ICBO |  |  | -0.1 | μA | VCB=-30 V, IE=0 | 2 |
| Emitter cut-off current | IEBO |  |  | -0.1 | μA | VEB=-5 V, IC=0 | 2 |
| DC current gain (BC857CW, BC858CW) | hFE | 420 |  | 800 |  | VCE= -5V, IC= -2mA | 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= -5 V, IC= -10mA, f=100MHz | 2 |
| Collector output capacitance | Cob |  |  | 4.5 | pF | VCB=-10V, f=1MHz | 2 |
| Collector-base voltage (BC858AW/BW/CW) | BVCBO | -30 |  |  | V | Ta=25℃ | 1 |
| Collector-emitter voltage (BC858AW/BW/CW) | BVCEO | -30 |  |  | V | Ta=25℃ | 1 |
| Emitter-base voltage | BVEBO |  |  | -6 | V | Ta=25℃ | 1 |
| Collector current, continuous | IC |  |  | -0.1 | A | Ta=25℃ | 1 |
| Collector power dissipation | PC |  |  | 200 | mW | Ta=25℃ | 1 |
| Junction temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Thermal resistance, junction to ambient | RΘJA |  |  | 625 | ℃/W |  | 1 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts |  | tin | ● Terminals: Tin plated leads, solderable per J-STD-002 and JESD22-B102 | 1 |

## CAD (KiCad official)

- Symbol: `BC858CW`
- Footprint: `Package_TO_SOT_SMD:SOT-323_SC-70`
- 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files: `bc858cw-etched.step` / `bc858cw-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc858cw.step` / `bc858cw.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Yangzhou Yangjie Elec Tech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588918574363000832) (5 pp, sha256 `4320f8b33b08bb7c`, retrieved 2026-10-19, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+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/bc858cw-datasheet.pdf)