# BC850BW

**Nexperia** · Bipolar (BJT) · SOT-323

BC850BW from Nexperia, 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 terminal of the NPN transistor (PINNING table, page 3). |
| 2 | emitter | passive | Emitter terminal of the NPN transistor (PINNING table, page 3). |
| 3 | collector | passive | Collector terminal of the NPN transistor; collector-emitter voltage is limited to -45 V for BC850W and collector current to -100 mA DC (limiting values, page 3). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Nexperia |
| 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 voltage (BC850W) | VCBO |  |  | -50 | V | open emitter | 3 |
| Collector-emitter voltage (BC850W) | VCEO |  |  | -45 | V | open base | 3 |
| Emitter-base voltage | VEBO |  |  | -5 | V | open collector | 3 |
| Collector current (DC) | IC |  |  | -100 | mA |  | 3 |
| Peak collector current | ICM |  |  | -200 | mA |  | 3 |
| Peak base current | IBM |  |  | -200 | mA |  | 3 |
| Total power dissipation | Ptot |  |  | 200 | mW | Tamb ≤ 25 °C; note 1 | 3 |
| Storage temperature | Tstg | -65 |  | 150 | °C |  | 3 |
| Junction temperature | Tj |  |  | 150 | °C |  | 3 |
| Operating ambient temperature | Tamb | -65 |  | 150 | °C |  | 3 |
| Thermal resistance from junction to ambient | Rth j-a |  | 625 |  | K/W | note 1 (FR4 printed-circuit board) | 4 |
| Collector cut-off current | ICBO |  |  | 15 | nA | IE = 0; VCB = 30 V | 4 |
| Collector cut-off current at Tj = 150 °C | ICBO |  |  | 5 | μA | IE = 0; VCB = 30 V; Tj = 150 °C | 4 |
| Emitter cut-off current | IEBO |  |  | 100 | nA | IC = 0; VEB = 5 V | 4 |
| DC current gain (BC849BW; BC850BW) | hFE | 200 |  | 450 |  | IC = 2 mA; VCE = 5 V; see Figs 2 and 3 | 4 |
| Collector-emitter saturation voltage | VCEsat |  |  | 250 | mV | IC = 10 mA; IB = 0.5 mA | 4 |
| Collector-emitter saturation voltage | VCEsat |  |  | 600 | mV | IC = 100 mA; IB = 5 mA; note 1 | 4 |
| Base-emitter voltage | VBE | 580 |  | 700 | mV | IC = 2 mA; VCE = 5 V | 4 |
| Base-emitter voltage | VBE |  |  | 770 | mV | IC = 10 mA; VCE = 5 V | 4 |
| Collector capacitance | Cc |  |  | 3 | pF | IE = ie = 0; VCB = 10 V; f = 1 MHz | 4 |
| Transition frequency | fT | 100 |  |  | MHz | IC = 10 mA; VCE = 5 V; f = 100 MHz | 4 |
| Noise figure | F |  |  | 4 | dB | IC = 200 μA; VCE = 5 V; RS = 2 kΩ; f = 10 Hz to 15.7 kHz | 4 |

## CAD (KiCad official)

- Symbol: `BC850BW`
- Footprint: `Package_TO_SOT_SMD:SOT-323_SC-70`
- 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files: `bc850bw-etched.step` / `bc850bw-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc850bw.step` / `bc850bw.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Nexperia datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588913337203220480) (8 pp, sha256 `5c01de813bd3be7c`, 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/bc850bw-datasheet.pdf)