component
BF840
Public Made by Adomby adom
Nexperia Bipolar (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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README
markdownBF840
Nexperia · Bipolar (BJT) · SOT-23
BF840 from Nexperia, 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 | passive | Base terminal of the NPN transistor; the datasheet gives the emitter-base limit VEBO of 4 V max (open collector) and a 25 mA maximum collector current. |
| 2 | E | passive | Emitter terminal of the NPN transistor; emitter-base voltage is limited to VEBO = 4 V (open collector), with the 25 mA maximum collector current and 40 V maximum collector-base and collector-emitter voltages referenced to it. |
| 3 | C | passive | Collector terminal of the NPN transistor; limited to VCBO = 40 V (open emitter) and VCEO = 40 V (open base), with a DC and peak collector current of 25 mA maximum. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Nexperia |
| Package | SOT-23 |
| 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 cut-off current | ICBO | 100 | nA | IE = 0; VCB = 20 V | 4 | ||
| Emitter cut-off current | IEBO | 100 | nA | IC = 0; VEB = 4 V | 4 | ||
| DC current gain | hFE | 67 | 222 | IC = 1 mA; VCE = 10 V | 4 | ||
| Base-emitter voltage | VBE | 675 | 725 | 775 | mV | IC = 1 mA; VCE = 10 V | 4 |
| Collector-base voltage | VCBO | 40 | V | open emitter | 3 | ||
| Collector-emitter voltage | VCEO | 40 | V | open base | 3 | ||
| Emitter-base voltage | VEBO | 4 | V | open collector | 3 | ||
| Collector current (DC) | IC | 25 | mA | 3 | |||
| Peak collector current | ICM | 25 | mA | 3 | |||
| Total power dissipation | Ptot | 250 | mW | Tamb ≤ 25 °C; note 1 | 3 | ||
| Storage temperature | Tstg | -65 | 150 | °C | 3 | ||
| Junction temperature | Tj | 150 | °C | 3 | |||
| Operating ambient temperature | Tamb | -65 | 150 | °C | 3 | ||
| Thermal resistance from junction to ambient | Rth(j-a) | 500 | K/W | note 1 (transistor mounted on FR4 PCB) | 4 |
CAD (KiCad official)
- Symbol:
BF840 - Footprint:
Package_TO_SOT_SMD:SOT-23 - 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files:
bf840-etched.step/bf840-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bf840.step/bf840.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Nexperia datasheet (7 pp, sha256
7c62d5cca3f51f7b, retrieved 2026-10-17, tier: manufacturer) - 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).