# BDX54C

**STMicroelectronics** · Darlington Transistors · TO-220

BDX54C from STMicroelectronics, in a TO-220. 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 | B | input | Base terminal of PNP Darlington transistor; maximum base current IB = 0.2 A, maximum base-emitter voltage VEBO = 5 V. |
| 2 | C | passive | Collector terminal (electrically connected to TAB for thermal contact); maximum collector current IC = 8 A continuous or ICM = 12 A peak, maximum collector-base voltage VCBO = 100 V, maximum collector-emitter voltage VCEO = 100 V. |
| 3 | E | passive | Emitter terminal with integrated antiparallel collector-emitter diode for reverse voltage protection; monolithic Darlington configuration. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | TO-220 |
| Category | Transistors/Thyristors |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `BDX54C`
- Footprint: `Package_TO_SOT_THT:TO-220-3_Vertical`
- 3D model: TO-220 (KiCad packages3D, STEP)
- 3D model files: `bdx54c-etched.step` / `bdx54c-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bdx54c.step` / `bdx54c.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [STMicroelectronics datasheet](https://www.st.com/resource/en/datasheet/bdx54c.pdf) (9 pp, sha256 `d560383e1ef85332`, retrieved 2026-09-23, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.2`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-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/bdx54c-datasheet.pdf)