# BC857BLT1G

**onsemi** · Bipolar (BJT) · SOT-23

BC857BLT1G from onsemi, 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 | BASE | input | Base terminal of the PNP transistor; the datasheet gives no separate pin limit, only the series maximum ratings (IC −100 mA continuous, −200 mA peak). |
| 2 | EMITTER | passive | Emitter terminal of the PNP transistor, with emitter-base voltage rated at −5.0 V maximum per the series maximum ratings. |
| 3 | COLLECTOR | passive | Collector terminal of the PNP transistor; for the BC857 series the datasheet lists VCEO −45 V and VCBO −50 V, with collector current −100 mA continuous. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SOT-23 |
| Category | Transistors/Thyristors |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `BC857BLT1G`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `bc857blt1g-etched.step` / `bc857blt1g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc857blt1g.step` / `bc857blt1g.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [onsemi datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8586180652576620544) (7 pp, sha256 `5b3358db41b73faa`, retrieved 2026-10-09, 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/bc857blt1g-datasheet.pdf)