# BC857BDW1T1G

**onsemi** · Bipolar (BJT) · SOT-363

BC857BDW1T1G from onsemi, in a SOT-363. 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 | EMITTER 2 | passive | Emitter terminal of Q2 with maximum emitter-base voltage rating of -5.0 V. |
| 2 | BASE 2 | input | Base terminal of Q2 for control of transistor conduction. |
| 3 | COLLECTOR 1 | output | Collector terminal of Q1 rated for maximum continuous current of -100 mA and collector-emitter voltage of -45 V. |
| 4 | EMITTER 1 | passive | Emitter terminal of Q1 with maximum emitter-base voltage rating of -5.0 V. |
| 5 | BASE 1 | input | Base terminal of Q1 for control of transistor conduction. |
| 6 | COLLECTOR 2 | output | Collector terminal of Q2 rated for maximum continuous current of -100 mA and collector-emitter voltage of -45 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SOT-363 |
| Category | Transistors/Thyristors |
| Pins | 6 |

## CAD (KiCad official)

- Symbol: `BC857BDW1T1G`
- Footprint: `Package_TO_SOT_SMD:SOT-363_SC-70-6`
- 3D model: SOT-363 (KiCad packages3D, STEP)
- 3D model files: `bc857bdw1t1g-etched.step` / `bc857bdw1t1g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc857bdw1t1g.step` / `bc857bdw1t1g.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/8586204661548662784) (7 pp, sha256 `3a5f33908380e4f2`, retrieved 2026-09-29, tier: lcsc)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/bc857bdw1t1g-datasheet.pdf)