component
BC857A-7-F
Public Made by Adomby adom
Diodes Incorporated Bipolar Transistors - BJT, SOT-23. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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Contents
README
markdownBC857A-7-F
Diodes Incorporated · Bipolar Transistors - BJT · SOT-23
BC857A-7-F from Diodes Incorporated, 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 | B | input | Base of the PNP transistor; VEBO is limited to -5.0 V and peak base current IBM to -200 mA (single pulse). |
| 2 | E | passive | Emitter of the PNP transistor; peak emitter current IEM is limited to -200 mA and VEBO to -5.0 V. |
| 3 | C | passive | Collector of the PNP transistor; for BC857A, VCBO is -50 V, VCEO is -45 V, continuous IC is -100 mA, and peak ICM is -200 mA. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Diodes Incorporated |
| Package | SOT-23 |
| 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 | 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 | 125 | 180 | 250 | 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) | -700 | mV | IC = -10mA, IB = -0.5mA | 4 | ||
| Base-Emitter Saturation Voltage | VBE(sat) | -850 | -1100 | mV | IC = -100mA, IB = -5mA | 4 | |
| Output Capacitance | Cobo | 3 | pF | VCB = -10V, f = 1.0MHz | 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 | BC857A/B/C | 2 | ||
| Collector-Emitter Voltage | VCEO | -45 | V | BC857A/B/C | 2 | ||
| Emitter-Base Voltage | VEBO | -5 | V | 2 | |||
| Continuous Collector Current | IC | -100 | mA | 2 | |||
| Peak Collector Current (Single Pulse) | ICM | -200 | mA | Single pulse | 2 | ||
| Peak Emitter Current | IEM | -200 | mA | 2 | |||
| Peak Base Current (Single Pulse) | IBM | -200 | mA | Single pulse | 2 | ||
| Operating and Storage Temperature Range | TJ, TSTG | -55 | 150 | °C | 2 | ||
| Power Dissipation | PD | 310 | mW | Note 5, minimum recommended pad layout on FR-4 | 2 | ||
| Power Dissipation | PD | 350 | mW | Note 6, 15mm x 15mm 1oz copper | 2 | ||
| Thermal Resistance, Junction to Ambient | RθJA | 403 | °C/W | Note 5, minimum recommended pad layout on FR-4 | 2 | ||
| Thermal Resistance, Junction to Ambient | RθJA | 357 | °C/W | Note 6, 15mm x 15mm 1oz copper | 2 | ||
| Thermal Resistance, Junction to Leads | RθJL | 350 | °C/W | Note 7, junction to solder-point | 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:
BC857A-7-F - Footprint:
Package_TO_SOT_SMD:SOT-23 - 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files:
bc857a-7-f-etched.step/bc857a-7-f-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bc857a-7-f.step/bc857a-7-f.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Diodes Incorporated datasheet (7 pp, sha256
9f19c49db2adb724, retrieved 2026-11-10, tier: manufacturer) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text+vision), consensusclaude-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).