# BC857BW-7-F

**Diodes Incorporated** · Bipolar Transistors - BJT · SOT-323

BC857BW-7-F from Diodes Incorporated, in a SOT-323. 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 | B | input | Base of the PNP transistor; the Emitter-Base voltage must not exceed -5.0 V (VEBO). |
| 2 | E | passive | Emitter of the PNP transistor; peak pulse emitter current (single pulse) is limited to -200 mA. |
| 3 | C | passive | Collector of the PNP transistor; continuous collector current is -100 mA max and peak pulse collector current is -200 mA, with VCEO of -45 V for the BC857 types. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Diodes Incorporated |
| Package | SOT-323 |
| Category | Transistors |
| 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 (BC857) | BVCBO | -50 |  |  | V | IC = -100µA | 3 |
| Collector-Emitter Breakdown Voltage (BC857) | BVCEO | -45 |  |  | V | IC = -10mA | 3 |
| Emitter-Base Breakdown Voltage | BVEBO | -5 |  |  | V | IE = -100µA | 3 |
| DC Current Gain (Group B) | hFE | 220 | 290 | 475 |  | VCE = -5.0V, IC = -2.0mA | 3 |
| Collector Cutoff Current | ICBO |  |  | -15 | nA | VCB = -30V | 3 |
| Collector Cutoff Current (TA = +150°C) | ICBO |  |  | -4 | µA | VCB = -30V, TA = +150°C | 3 |
| Collector-Emitter Saturation Voltage | VCE(sat) |  | -75 | -300 | mV | IC = -10mA, IB = -0.5mA | 3 |
| Collector-Emitter Saturation Voltage | VCE(sat) |  | -250 | -650 | mV | IC = -100mA, IB = -5.0mA | 3 |
| Base-Emitter Turn-On Voltage | VBE(on) | -600 | -650 | -750 | mV | IC = -2mA, VCE = -5V | 3 |
| Base-Emitter Turn-On Voltage | VBE(on) |  |  | -820 | mV | IC = -10mA, VCE = -5V | 3 |
| Base-Emitter Saturation Voltage | VBE(sat) |  | -700 |  | mV | IC = -10mA, IB = -0.5mA | 3 |
| Base-Emitter Saturation Voltage | VBE(sat) |  | -850 | -950 | mV | IC = -100mA, IB = -5mA | 3 |
| Output Capacitance | Cobo |  | 3 | 4.5 | pF | VCB = -10V, f = 1.0MHz | 3 |
| Transition Frequency | fT | 100 | 200 |  | MHz | VCE = -5V, IC = -10mA, f = 100MHz | 3 |
| Noise Figure | NF |  |  | 10 | dB | VCE = -5V, IC = -200µA, RS = 2kΩ, f = 1kHz, Δf = 200Hz | 3 |
| Collector-Base Voltage (BC857) | VCBO |  |  | -50 | V |  | 2 |
| Collector-Emitter Voltage (BC857) | VCEO |  |  | -45 | V |  | 2 |
| Emitter-Base Voltage | VEBO |  |  | -5 | V |  | 2 |
| Continuous Collector Current | IC |  |  | -100 | mA |  | 2 |
| Peak Pulse Collector Current | ICM |  |  | -200 | mA | single pulse | 2 |
| Peak Pulse Emitter Current | IEM |  |  | -200 | mA | single pulse | 2 |
| Power Dissipation | PD |  |  | 200 | mW | Note 5 | 2 |
| Thermal Resistance, Junction to Ambient | RϴJA |  | 625 |  | °C/W | Note 5 | 2 |
| Operating and Storage Temperature Range | TJ, TSTG | -55 |  | 150 | °C |  | 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 (KiCad official)

- Symbol: `BC857BW-7-F`
- Footprint: `Package_TO_SOT_SMD:SOT-323_SC-70`
- 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files: `bc857bw-7-f-etched.step` / `bc857bw-7-f-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc857bw-7-f.step` / `bc857bw-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/BC857BW-7-F.pdf) (6 pp, sha256 `8524b3f1e7fd66f2`, retrieved 2026-11-09, tier: manufacturer)
- **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/bc857bw-7-f-datasheet.pdf)