# BFS19

**Nexperia** · Bipolar (BJT) · SOT-23

BFS19 from Nexperia, in a SOT-23. 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 | passive | Base terminal of the NPN transistor; the datasheet gives no base-specific limit, and the emitter-base limit is VEBO = 5 V max with collector open. |
| 2 | E | passive | Emitter terminal of the NPN transistor; the emitter-base voltage limit is VEBO = 5 V max with collector open. |
| 3 | C | passive | Collector terminal of the NPN transistor; limits are VCBO = 30 V max (open emitter), VCEO = 20 V max (open base), and IC = 30 mA max DC. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Nexperia |
| Package | SOT-23 |
| 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 | VCBO |  |  | 30 | V | open emitter | 4 |
| collector-emitter voltage | VCEO |  |  | 20 | V | open base | 4 |
| emitter-base voltage | VEBO |  |  | 5 | V | open collector | 4 |
| collector current (DC) | IC |  |  | 30 | mA |  | 4 |
| peak collector current | ICM |  |  | 30 | mA |  | 4 |
| total power dissipation | Ptot |  |  | 250 | mW | Tamb ≤ 25 °C; note 1 | 4 |
| storage temperature | Tstg | -65 |  | 150 | °C |  | 4 |
| junction temperature | Tj |  |  | 150 | °C |  | 4 |
| operating ambient temperature | Tamb | -65 |  | 150 | °C |  | 4 |
| collector cut-off current | ICBO |  |  | 100 | nA | IE = 0; VCB = 20 V | 5 |
| collector cut-off current | ICBO |  |  | 10 | µA | IE = 0; VCB = 20 V; Tj = 100 °C | 5 |
| emitter cut-off current | IEBO |  |  | 100 | nA | IC = 0; VEB = 5 V | 5 |
| DC current gain | hFE | 65 |  | 225 |  | IC = 1 mA; VCE = 10 V | 5 |
| base-emitter voltage | VBE | 650 |  | 740 | mV | IC = 1 mA; VCE = 10 V | 5 |
| thermal resistance from junction to ambient | Rth(j-a) |  | 500 |  | K/W | note 1 (transistor mounted on FR4 PCB) | 5 |

## CAD (KiCad official)

- Symbol: `BFS19`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `bfs19-etched.step` / `bfs19-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bfs19.step` / `bfs19.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Nexperia datasheet](https://assets.nexperia.com/documents/data-sheet/BFS19.pdf) (8 pp, sha256 `1781f890b6ba5a47`, retrieved 2026-10-17, tier: manufacturer)
- **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/bfs19-datasheet.pdf)