# BC556BTA

**onsemi** · Bipolar (BJT) · TO-92-3

BC556BTA from onsemi, in a TO-92-3. 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 | Collector | passive | Collector terminal of the PNP transistor; for BC556 the collector-emitter voltage is limited to -65 V and DC collector current to -100 mA (peak pulse -200 mA). |
| 2 | Base | passive | Base terminal of the PNP transistor; peak base current is limited to -200 mA (pulsed), per the absolute maximum ratings. |
| 3 | Emitter | passive | Emitter terminal of the PNP transistor; emitter-base voltage is limited to -5 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | TO-92-3 |
| 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 Voltage (BC556) | VCBO |  |  | -80 | V |  | 3 |
| Collector-Emitter Voltage (BC556) | VCEO |  |  | -65 | V |  | 3 |
| Emitter-Base Voltage | VEBO |  |  | -5 | V |  | 3 |
| Collector Current (DC) | IC |  |  | -100 | mA |  | 3 |
| Peak Collector Current (Pulse) | ICP |  |  | -200 | mA |  | 3 |
| Peak Base Current (Pulse) | IBP |  |  | -200 | mA |  | 3 |
| Junction Temperature | TJ |  |  | 150 | °C |  | 3 |
| Storage Temperature Range | TSTG | -65 |  | 150 | °C |  | 3 |
| Total Power Dissipation | PD |  |  | 500 | mW |  | 3 |
| Thermal Resistance, Junction-to-Ambient | RθJA |  |  | 250 | °C/W |  | 3 |
| Collector Cut-Off Current | ICBO |  |  | -15 | nA | VCB = -30 V, IE = 0 | 4 |
| DC Current Gain | hFE | 110 |  | 800 |  | VCE = -5 V, IC = -2 mA | 4 |
| DC Current Gain, hFE classification B (BC556B) | hFE | 200 |  | 450 |  |  | 4 |
| Collector-Emitter Saturation Voltage | VCE(sat) |  | -90 | -300 | mV | IC = -10 mA, IB = -0.5 mA | 4 |
| Collector-Emitter Saturation Voltage | VCE(sat) |  | -250 | -650 | mV | IC = -100 mA, IB = -5 mA | 4 |
| Collector-Base Saturation Voltage | VBE(sat) |  |  | -700 | mV | IC = -10 mA, IB = -0.5 mA | 4 |
| Collector-Base Saturation Voltage | VBE(sat) |  |  | -900 | mV | IC = -100 mA, IB = -5 mA | 4 |
| Base-Emitter On Voltage | VBE(on) | -600 | -660 | -750 | mV | VCE = -5 V, IC = -2 mA | 4 |
| Base-Emitter On Voltage | VBE(on) |  |  | -800 | mV | VCE = -5 V, IC = -10 mA | 4 |
| Noise Figure (BC556/BC557/BC558) | NF |  | 2 | 10 | dB | VCE = -5 V, IC = -200 μA, f = 1 kHz, RG = 2 kΩ | 4 |
| Current Gain Bandwidth Product | fT |  | 150 |  | MHz | VCE = -5 V, IC = -10 mA, f = 10 MHz | 4 |
| Output Capacitance | Cob |  | 6 |  | pF | VCB = -10 V, IE = 0, f = 1 MHz | 4 |

## CAD (KiCad official)

- Symbol: `BC556BTA`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92-3 (KiCad packages3D, STEP)
- 3D model files: `bc556bta-etched.step` / `bc556bta-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc556bta.step` / `bc556bta.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/8588895832515227648) (10 pp, sha256 `dc6bc4e39491d268`, retrieved 2026-10-18, 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/bc556bta-datasheet.pdf)