# BCX55-16U

**CBI** · Bipolar (BJT) · SOT-89

BCX55-16U from CBI, in a SOT-89. 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 of the NPN transistor; emitter-base voltage is rated at 5 V maximum (VEBO). |
| 2 | Collector | passive | Collector of the NPN transistor; collector current is rated at 1 A, and VCEO is 60 V for the BCX55 family. |
| 3 | Emitter | passive | Emitter of the NPN transistor; it is the common terminal, and the package dissipates 500 mW. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | CBI |
| Package | SOT-89 |
| 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-Emitter breakdown voltage (BCX55) | V(BR)CEO | 60 |  |  | V | IC=10mA,IB=0 | 2 |
| Collector-base breakdown voltage (BCX55) | V(BR)CBO | 60 |  |  | V | IC=100µA,IE=0 | 2 |
| Emitter-base breakdown voltage | V(BR)EBO | 5 |  |  | V | IE=100µA,IC=0 | 2 |
| Collector cut-off current | ICBO |  |  | 0.1 | µA | VCB=30V,IE=0 | 2 |
| Emitter cut-off current | IEBO |  |  | 0.1 | µA | VEB=5V,IC=0 | 2 |
| DC current gain | hFE(1) | 40 |  |  |  | VCE=2V, IC=5mA | 2 |
| DC current gain | hFE(2) | 63 |  | 250 |  | VCE=2V, IC=150mA | 2 |
| DC current gain | hFE(3) | 25 |  |  |  | VCE=2V, IC=0.5A | 2 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | 0.5 | V | IC=0.5A,IB=50mA | 2 |
| Base-emitter voltage | VBE |  |  | 1 | V | VCE=2V, IC=0.5A | 2 |
| Transition frequency | fT |  | 130 |  | MHz | VCE=5V,IC=10mA, f=100MHz | 2 |
| Collector-Base Voltage (BCX55) | VCBO |  |  | 60 | V |  | 1 |
| Collector-Emitter Voltage (BCX55) | VCEO |  |  | 60 | V |  | 1 |
| Emitter-Base Voltage | VEBO |  |  | 5 | V |  | 1 |
| Collector Current | IC |  |  | 1 | A |  | 1 |
| Collector Power Dissipation | PC |  |  | 500 | mW |  | 1 |
| Junction Temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage Temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Thermal Resistance From Junction To Ambient | RθJA |  |  | 250 | ℃/W |  | 1 |

## CAD (KiCad official)

- Symbol: `BCX55-16U`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89 (KiCad packages3D, STEP)
- 3D model files: `bcx55-16u-etched.step` / `bcx55-16u-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bcx55-16u.step` / `bcx55-16u.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [CBI datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8756592999860592640) (3 pp, sha256 `4d1dcd763ce173a6`, retrieved 2026-10-18, 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/bcx55-16u-datasheet.pdf)