# BC817-40

**UMW** · Bipolar (BJT) · SOT-23-3

BC817-40 from UMW, in a SOT-23-3. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | BASE | input | Base terminal of NPN transistor; maximum collector-base voltage is 50 V. |
| 2 | EMITTER | passive | Emitter terminal of NPN transistor; maximum emitter-base voltage is 5 V. |
| 3 | COLLECTOR | passive | Collector terminal of NPN transistor; maximum collector-emitter voltage is 45 V and maximum continuous collector current is 0.5 A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | UMW |
| Package | SOT-23-3 |
| 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 | VCBO | 50 |  |  | V | IC= 10μA, IE=0 | 1 |
| Collector-emitter breakdown voltage | VCEO | 45 |  |  | V | IC= 10mA, IB=0 | 1 |
| Emitter-base breakdown voltage | VEBO | 5 |  |  | V | IE= 1μA, IC=0 | 1 |
| Collector cutoff current | ICBO |  |  | 0.1 | μA | VCB= 45 V, IE=0 | 1 |
| Emitter cutoff current | IEBO |  |  | 0.1 | μA | VEB= 4V, IC=0 | 1 |
| DC current gain hFE(1) | hFE(1) | 100 |  | 600 |  | VCE= 1V, IC= 100mA | 1 |
| DC current gain hFE(2) | hFE(2) | 40 |  |  |  | VCE= 1V, IC= 500mA | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | 0.7 | V | IC= 500mA, IB= 50mA | 1 |
| Base-emitter saturation voltage | VBE(sat) |  |  | 1.2 | V | IC= 500mA, IB= 50mA | 1 |
| Base-emitter voltage | VBE |  |  | 1.2 | V | VCE= 1 V, IC= 500mA | 1 |
| Collector capacitance | Cob |  |  | 10 | pF | VCB=10V, f=1MHz | 1 |
| Transition frequency | fT | 100 |  |  | MHz | VCE= 5 V, IC= 10mA, f=100MHz | 1 |
| Collector-base voltage | VCBO |  |  | 50 | V | Ta=25℃ unless otherwise noted | 1 |
| Collector-emitter voltage | VCEO |  |  | 45 | V | Ta=25℃ unless otherwise noted | 1 |
| Emitter-base voltage | VEBO |  |  | 5 | V | Ta=25℃ unless otherwise noted | 1 |
| Collector current, continuous | IC |  |  | 0.5 | A | Ta=25℃ unless otherwise noted | 1 |
| Collector power dissipation | PC |  |  | 0.3 | W | Ta=25℃ unless otherwise noted | 1 |
| Junction temperature | TJ |  |  | 150 | ℃ |  | 1 |
| Storage temperature | TSTG | -55 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `BC817-40`
- Footprint: `Package_TO_SOT_SMD:SOT-23-3`
- 3D model: SOT-23-3 (KiCad packages3D, STEP)
- 3D model files: `bc817-40-etched.step` / `bc817-40-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc817-40.step` / `bc817-40.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [UMW datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588893218427031552) (3 pp, sha256 `691dd222da71b060`, retrieved 2026-09-21, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.2`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-4-6` (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/bc817-40-datasheet.pdf)