# BC556BBK

**DIOTEC** · Bipolar (BJT) · TO-92

BC556BBK from DIOTEC, in a TO-92. 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 | C | passive | Collector of the PNP transistor; maximum collector current is -100 mA DC (-200 mA peak) and VCEO is -65 V for the BC556. |
| 2 | B | passive | Base of the PNP transistor; peak base current is limited to 200 mA and VEBO to 5 V. |
| 3 | E | passive | Emitter of the PNP transistor; peak emitter current is limited to 200 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | DIOTEC |
| Package | TO-92 |
| 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 |
|---|---|---|---|---|---|---|---|
| DC current gain, Group B, IC = -2 mA | hFE | 200 |  | 450 |  | VCE = -5 V, IC = -2 mA, Group B | 2 |
| Collector-Emitter cutoff current, Tj = 25°C, BC556 | ICES |  | 0.2 | 15 | nA | VCE = -80 V, B-E short, BC556 | 2 |
| Collector-Emitter cutoff current, Tj = 125°C, BC556 | ICES |  |  | 4 | µA | Tj = 125°C, VCE = -80 V, B-E short, BC556 | 2 |
| Collector-Emitter saturation voltage, 10 mA / 0.5 mA | VCEsat |  | 80 | 300 | mV | IC = -10 mA, IB = -0.5 mA | 2 |
| Collector-Emitter saturation voltage, 100 mA / 5 mA | VCEsat |  | 250 | 650 | mV | IC = -100 mA, IB = -5 mA | 2 |
| Base-Emitter voltage, 2 mA | VBE | 600 | 660 | 750 | mV | VCE = -5 V, IC = -2 mA | 2 |
| Base-Emitter voltage, 10 mA | VBE |  |  | 820 | mV | VCE = -5 V, IC = -10 mA | 2 |
| Collector-Base capacitance | CCBO |  | 3.5 | 6 | pF | VCB = -10 V, IE = ie = 0, f = 1 MHz | 2 |
| Noise figure, BC556 to BC558 | F |  | 2 | 10 | dB | VCE = -5 V, IC = -200 µA, RG = 2 kΩ, f = 1 kHz, Δf = 200 Hz | 2 |
| Collector-Emitter voltage, E-B short (BC556) | VCES |  |  | 80 | V | E-B short | 1 |
| Collector-Emitter voltage, B open (BC556) | VCEO |  |  | 65 | V | B open | 1 |
| Collector-Base voltage, E open (BC556) | VCBO |  |  | 80 | V | E open | 1 |
| Emitter-Base voltage | VEBO |  |  | 5 | V | C open | 1 |
| Power dissipation | Ptot |  |  | 500 | mW | Valid if leads kept at TA at 2 mm distance from case | 1 |
| Collector current DC | IC |  |  | 100 | mA | DC | 1 |
| Peak collector current | ICM |  |  | 200 | mA |  | 1 |
| Peak base current | IBM |  |  | 200 | mA |  | 1 |
| Peak emitter current | IEM |  |  | 200 | mA |  | 1 |
| Junction temperature | Tj | -55 |  | 150 | °C |  | 1 |
| Storage temperature | TS | -55 |  | 150 | °C |  | 1 |
| Typical thermal resistance junction to ambient | RthA |  | 200 |  | K/W | Valid if leads kept at ambient temperature at 2 mm distance from case | 2 |

## CAD (KiCad official)

- Symbol: `BC556BBK`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92 (KiCad packages3D, STEP)
- 3D model files: `bc556bbk-etched.step` / `bc556bbk-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc556bbk.step` / `bc556bbk.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [DIOTEC datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590459117572816896) (4 pp, sha256 `f2051b60b559de98`, retrieved 2026-10-10, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-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/bc556bbk-datasheet.pdf)