component
BC857W-QX
Public Made by Adomby adom
Nexperia Bipolar (BJT), SOT-323. 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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README
markdownBC857W-QX
Nexperia · Bipolar (BJT) · SOT-323
BC857W-QX from Nexperia, 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 | passive | Base terminal; the datasheet limits peak base current IBM to -200 mA for this device family (BC856W-Q/BC857W-Q/BC858W-Q). |
| 2 | E | passive | Emitter terminal; the emitter-base voltage VEBO is limited to -5 V with open collector. |
| 3 | C | passive | Collector terminal; for BC857W-Q the collector-emitter voltage VCEO is -45 V (open base) and collector current IC is limited to -100 mA (peak ICM -200 mA). |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Nexperia |
| Package | SOT-323 |
| 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 | V(BR)CBO | -50 | V | IC = -100 µA; IE = 0 A | 5 | ||
| Collector-emitter breakdown voltage | V(BR)CEO | -45 | V | IC = -2 mA; IB = 0 A | 5 | ||
| Emitter-base breakdown voltage | V(BR)EBO | -5 | V | IC = 0 A; IE = -100 µA | 5 | ||
| Collector-base cut-off current | ICBO | -1 | -15 | nA | VCB = -30 V; IE = 0 A | 5 | |
| Collector-base cut-off current at Tj = 150 °C | ICBO | -4 | µA | VCB = -30 V; IE = 0 A; Tj = 150 °C | 5 | ||
| Emitter-base cut-off current | IEBO | -100 | nA | VEB = -5 V; IC = 0 A | 5 | ||
| DC current gain (BC857W-Q) | hFE | 125 | 800 | VCE = -5 V; IC = -2 mA | 5 | ||
| Collector-emitter saturation voltage | VCEsat | -75 | -300 | mV | IC = -10 mA; IB = -0.5 mA | 5 | |
| Collector-emitter saturation voltage | VCEsat | -250 | -600 | mV | IC = -100 mA; IB = -5 mA; pulsed; tp ≤ 300 μs; δ ≤ 0.02 | 5 | |
| Base-emitter voltage | VBE | -600 | -650 | -750 | mV | VCE = -5 V; IC = -2 mA | 5 |
| Base-emitter voltage | VBE | -820 | mV | VCE = -5 V; IC = -10 mA | 5 | ||
| Transition frequency | fT | 100 | MHz | VCE = -5 V; IC = -10 mA; f = 100 MHz | 5 | ||
| Noise figure | NF | 2 | 10 | dB | IC = -200 µA; VCE = -5 V; RS = 2 kΩ; f = 1 kHz; B = 200Hz | 5 | |
| Collector-base voltage | VCBO | -50 | V | open emitter | 3 | ||
| Collector-emitter voltage | VCEO | -45 | V | open base | 3 | ||
| Emitter-base voltage | VEBO | -5 | V | open collector | 3 | ||
| Collector current | IC | -100 | mA | 3 | |||
| Peak collector current | ICM | -200 | mA | 3 | |||
| Peak base current | IBM | -200 | mA | 3 | |||
| Total power dissipation | Ptot | 200 | mW | Tamb ≤ 25 °C | 3 | ||
| Junction temperature | Tj | 150 | °C | 3 | |||
| Ambient temperature | Tamb | -65 | 150 | °C | 3 | ||
| Storage temperature | Tstg | -65 | 150 | °C | 3 | ||
| Thermal resistance from junction to ambient | Rth(j-a) | 625 | K/W | in free air; FR4 PCB, single-sided, 35 µm copper, tin-plated, standard footprint | 4 |
CAD (KiCad official)
- Symbol:
BC857W-QX - Footprint:
Package_TO_SOT_SMD:SOT-323_SC-70 - 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files:
bc857w-qx-etched.step/bc857w-qx-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bc857w-qx.step/bc857w-qx.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Nexperia datasheet (13 pp, sha256
4832a02efea5b89a, retrieved 2026-10-17, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-5-5(text), consensusclaude-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).