# BCX17LT1G

**onsemi** · Bipolar (BJT) · SOT-23

BCX17LT1G from onsemi, in a SOT-23. 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 terminal of the transistor; the datasheet specifies base drive only through test conditions, such as IB = 50 mAdc at IC = 500 mAdc for VCE(sat). |
| 2 | EMITTER | passive | Emitter terminal; the emitter-base voltage is rated at VEBO = 5.0 Vdc maximum. |
| 3 | COLLECTOR | passive | Collector terminal; rated VCEO 45 Vdc (BCX17/BCX19) or 25 Vdc (BCX18), VCBO 50 Vdc or 30 Vdc, and continuous collector current IC 500 mAdc. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SOT-23 |
| 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 (BCX17) | V(BR)CEO | 45 |  |  | Vdc | IC = 10 mAdc, IB = 0 | 2 |
| Collector-Emitter Breakdown Voltage (BCX17) | V(BR)CES | 50 |  |  | Vdc | IC = 10 Adc, IC = 0 | 2 |
| Collector Cutoff Current | ICBO |  |  | 100 | nAdc | VCB = 20 Vdc, IE = 0 | 2 |
| Collector Cutoff Current | ICBO |  |  | 5 | Adc | VCB = 20 Vdc, IE = 0, TA = 150°C | 2 |
| Emitter Cutoff Current | IEBO |  |  | 10 | Adc | VEB = 5.0 Vdc, IC = 0 | 2 |
| DC Current Gain | hFE | 100 |  | 600 |  | IC = 100 mAdc, VCE = 1.0 Vdc | 2 |
| DC Current Gain | hFE | 70 |  |  |  | IC = 300 mAdc, VCE = 1.0 Vdc | 2 |
| DC Current Gain | hFE | 40 |  |  |  | IC = 500 mAdc, VCE = 1.0 Vdc | 2 |
| Collector-Emitter Saturation Voltage | VCE(sat) |  |  | 0.62 | Vdc | IC = 500 mAdc, IB = 50 mAdc | 2 |
| Base-Emitter On Voltage | VBE(on) |  |  | 1.2 | Vdc | IC = 500 mAdc, VCE = 1.0 Vdc | 2 |
| Collector-Emitter Voltage (BCX17, BCX19) | VCEO |  |  | 45 | Vdc |  | 1 |
| Collector-Base Voltage (BCX17, BCX19) | VCBO |  |  | 50 | Vdc |  | 1 |
| Emitter-Base Voltage | VEBO |  |  | 5 | Vdc |  | 1 |
| Collector Current - Continuous | IC |  |  | 500 | mAdc |  | 1 |
| Total Device Dissipation (FR-5 Board) | PD |  |  | 225 | mW | FR-5 Board (Note 1), TA = 25°C | 1 |
| Derate above 25°C (FR-5 Board) | PD |  |  | 1.8 | mW/°C | Derate above 25°C | 1 |
| Thermal Resistance, Junction-to-Ambient (FR-5 Board) | RJA |  |  | 556 | °C/W | FR-5 Board (Note 1) | 1 |
| Total Device Dissipation (Alumina Substrate) | PD |  |  | 300 | mW | Alumina Substrate (Note 2), TA = 25°C | 1 |
| Derate above 25°C (Alumina Substrate) | PD |  |  | 2.4 | mW/°C | Derate above 25°C | 1 |
| Thermal Resistance, Junction-to-Ambient (Alumina Substrate) | RJA |  |  | 417 | °C/W | Alumina Substrate (Note 2) | 1 |
| Junction and Storage Temperature | TJ, Tstg | -55 |  | 150 | °C |  | 1 |

## CAD (KiCad official)

- Symbol: `BCX17LT1G`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `bcx17lt1g-etched.step` / `bcx17lt1g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bcx17lt1g.step` / `bcx17lt1g.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/8588885167557783552) (5 pp, sha256 `239bfa6b037c5532`, retrieved 2026-10-20, 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/bcx17lt1g-datasheet.pdf)