# BC857DW

**CBI** · Bipolar Transistors - BJT · SOT-363

BC857DW from CBI, in a SOT-363. 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 | E1 | passive | Emitter of PNP transistor 1 (Q1); VEBO max -5 V. |
| 2 | B1 | passive | Base of PNP transistor 1 (Q1); VBE -0.6 to -0.75 V at VCE=-5 V, IC=-2 mA. |
| 3 | C2 | passive | Collector of PNP transistor 2 (Q2); VCEO max -45 V, continuous IC max -0.2 A. |
| 4 | E2 | passive | Emitter of PNP transistor 2 (Q2); VEBO max -5 V. |
| 5 | B2 | passive | Base of PNP transistor 2 (Q2); VBE -0.6 to -0.75 V at VCE=-5 V, IC=-2 mA. |
| 6 | C1 | passive | Collector of PNP transistor 1 (Q1); VCEO max -45 V, continuous IC max -0.2 A. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | CBI |
| Package | SOT-363 |
| Category | Transistors |
| Pins | 6 |

## 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 | V(BR)CBO | -50 |  |  | V | Ic=-10µA,IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | -45 |  |  | V | Ic=-10mA,IB=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | -5 |  |  | V | IE=-10µA,IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | -15 | nA | VCB=-30V,IE=0 | 1 |
| DC current gain | hFE | 125 |  | 630 |  | VCE=-5V,IC=-2mA | 1 |
| Collector-emitter saturation voltage (1) | VCE(sat)(1) |  |  | -0.3 | V | IC=-10mA,IB=-0.5mA | 1 |
| Collector-emitter saturation voltage (2) | VCE(sat)(2) |  |  | -0.65 | V | IC=-100mA,IB=-5mA | 1 |
| Base-emitter voltage (1) | VBE(1) | -0.6 |  | -0.75 | V | VCE=-5V,IC=-2mA | 1 |
| Base-emitter voltage (2) | VBE(2) |  |  | -0.82 | V | VCE=-5V,IC=-10mA | 1 |
| Transition frequency | fT | 200 |  |  | MHz | VCE=-5V,IC=-10mA,f=100MHz | 1 |
| Collector output capacitance | Cob |  |  | 3.5 | pF | VCB=-10V,IE=0,f=1MHz | 1 |
| Noise figure | NF |  |  | 2.5 | dB | VCE=-5V,Ic=-0.2mA, f=1kHZ,Rs=2KΩ,BW=200Hz | 1 |
| Collector-Base Voltage | VCBO |  |  | -50 | V | Ta=25℃ | 1 |
| Collector-Emitter Voltage | VCEO |  |  | -45 | V | Ta=25℃ | 1 |
| Emitter-Base Voltage | VEBO |  |  | -5 | V | Ta=25℃ | 1 |
| Collector Current -Continuous | IC |  |  | -0.2 | A | Ta=25℃ | 1 |
| Collector Power Dissipation | PC |  |  | 0.3 | W | Ta=25℃ | 1 |
| Junction Temperature | TJ |  |  | 150 | ℃ | Ta=25℃ | 1 |
| Storage Temperature | Tstg | -55 |  | 150 | ℃ | Ta=25℃ | 1 |
| Thermal Resistance from Junction to Ambient | RθJA |  | 417 |  | ℃/W | Ta=25℃ | 1 |

## CAD (KiCad official)

- Symbol: `BC857DW`
- Footprint: `Package_TO_SOT_SMD:SOT-363_SC-70-6`
- 3D model: SOT-363 (KiCad packages3D, STEP)
- 3D model files: `bc857dw-etched.step` / `bc857dw-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc857dw.step` / `bc857dw.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [CBI datasheet](docs/bc857dw-datasheet.pdf) (3 pp, sha256 `7b3b0f62fea80721`, retrieved 2026-10-27, 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/bc857dw-datasheet.pdf)