# BC857CQ-7-F

**Diodes Incorporated** · Bipolar (BJT) · SOT-23-3

BC857CQ-7-F from Diodes Incorporated, in a SOT-23-3. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model). Symbol and footprint from KiCad-official CAD; the 3D model is generated from the datasheet's package dimensions.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | B | passive | Base terminal; the peak base current IBM is limited to -200 mA. |
| 2 | E | passive | Emitter terminal; the emitter-base voltage VEBO is -5.0 V and the peak emitter current IEM is -200 mA. |
| 3 | C | passive | Collector terminal; the collector-emitter voltage VCEO is -45 V and the continuous collector current IC is -100 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Diodes Incorporated |
| Package | SOT-23-3 |
| 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 Breakdown Voltage | BVCBO | -50 |  |  | V | IC = -10µA | 4 |
| Collector-Emitter Breakdown Voltage | BVCEO | -45 |  |  | V | IC = -10mA | 4 |
| Emitter-Base Breakdown Voltage | BVEBO | -5 |  |  | V | IE = -1µA | 4 |
| Collector Cutoff Current | ICBO |  |  | -15 | nA | VCB = -30V | 4 |
| Collector Cutoff Current | ICBO |  |  | -4 | µA | VCB = -30V, TJ = +150°C | 4 |
| Collector Emitter Cutoff Current | ICES |  |  | -15 | nA | VCE = -50V | 4 |
| Emitter-Base Cutoff Current | IEBO |  |  | -100 | nA | VEB = -5V | 4 |
| DC Current Gain | hFE | 420 | 520 | 800 |, | IC = -2.0mA, VCE = -5V | 4 |
| Collector-Emitter Saturation Voltage | VCE(SAT) |  | -75 | -300 | mV | IC = -10mA, IB = -0.5mA | 4 |
| Collector-Emitter Saturation Voltage | VCE(SAT) |  | -250 | -650 | mV | IC = -100mA, IB = -5.0mA | 4 |
| Base-Emitter Turn-On Voltage | VBE(ON) | -600 | -650 | -750 | mV | IC = -2mA, VCE = -5V | 4 |
| Base-Emitter Turn-On Voltage | VBE(ON) |  |  | -820 | mV | IC = -10mA, VCE = -5V | 4 |
| Base-Emitter Saturation Voltage | VBE(SAT) |  | -850 | -1100 | mV | IC = -100mA, IB = -5mA | 4 |
| Transition Frequency | fT | 100 | 200 |  | MHz | VCE = -5V, IC = -10mA, f = 100MHz | 4 |
| Noise Figure | NF |  | 2 | 10 | dB | VCE = -5V, IC = -200µA, RS = 2kΩ, f = 1kHz, Δf = 200Hz | 4 |
| Collector-Base Voltage | VCBO |  |  | -50 | V | TA = +25°C | 2 |
| Collector-Emitter Voltage | VCEO |  |  | -45 | V | TA = +25°C | 2 |
| Emitter-Base Voltage | VEBO |  |  | -5 | V | TA = +25°C | 2 |
| Continuous Collector Current | IC |  |  | -100 | mA | TA = +25°C | 2 |
| Peak Collector Current | ICM |  |  | -200 | mA | TA = +25°C | 2 |
| Peak Emitter Current | IEM |  |  | -200 | mA | TA = +25°C | 2 |
| Peak Base Current | IBM |  |  | -200 | mA | TA = +25°C | 2 |
| Power Dissipation | PD |  |  | 310 | mW | Note 6 (minimum recommended pad layout, 1oz copper, single-sided FR-4), TA = +25°C | 2 |
| Power Dissipation | PD |  |  | 350 | mW | Note 7 (15mm x 15mm 1oz copper), TA = +25°C | 2 |
| Thermal Resistance, Junction to Ambient | RθJA |  | 403 |  | °C/W | Note 6, TA = +25°C | 2 |
| Thermal Resistance, Junction to Ambient | RθJA |  | 357 |  | °C/W | Note 7, TA = +25°C | 2 |
| Thermal Resistance, Junction to Leads | RθJL |  | 350 |  | °C/W | Note 8 (junction to solder point) | 2 |
| Operating and Storage Temperature Range | TJ, TSTG | -65 |  | 150 | °C |  | 2 |
| Electrostatic Discharge - Human Body Model | ESD HBM |  |  | 4000 | V | JEDEC Class 3A (Note 9) | 2 |
| Electrostatic Discharge - Machine Model | ESD MM |  |  | 400 | V | JEDEC Class C (Note 9) | 2 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts |  | tin |  Terminals: Finish, Matte Tin Plated Leads, Solderable per MIL-STD-202, Method 208 | 1 |

## CAD (land: KiCad; 3D: generated from the datasheet)

- Symbol: `BC857CQ-7-F`
- Footprint: `Package_TO_SOT_SMD:SOT-23-3`
- 3D model: SOT-23-3, generated on the KiCad land (body 1.3 x 2.9 mm, terminals on the pads, 1.025 mm tall, datasheet A, nominal). KiCad's stock model for this land is taller than the datasheet allows, so the model is generated from the datasheet drawing; the dimensions come from the datasheet drawing where it was read and are defaults otherwise (see provenance.model_3d_generated), not the manufacturer's CAD (STEP)
- 3D model files: `bc857cq-7-f-etched.step` / `bc857cq-7-f-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc857cq-7-f.step` / `bc857cq-7-f.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Diodes Incorporated datasheet](https://www.diodes.com/assets/Datasheets/BC857CQ-7-F.pdf) (7 pp, sha256 `ce26d6bf1b6f9359`, retrieved 2026-11-12, tier: manufacturer)
- **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:** land: KiCad official libraries (CC-BY-SA 4.0); 3D: generated from the datasheet's package dimensions (provenance.model_3d_generated).

[Datasheet PDF](docs/bc857cq-7-f-datasheet.pdf)