component
BF420
Public Made by Adomby adom
Changjing Bipolar (BJT), TO-92. 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
markdownBF420
Changjing · Bipolar (BJT) · TO-92
BF420 from Changjing, in a TO-92. 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 | EMITTER | passive | Emitter terminal of the NPN transistor, with a maximum emitter-base voltage VEBO of 5 V and a maximum continuous collector current of 100 mA stated for the device. |
| 2 | COLLECTOR | passive | Collector terminal of the NPN transistor, rated for a collector-emitter voltage VCEO of 300 V (BF420) or 250 V (BF422) and a continuous collector current of 100 mA. |
| 3 | BASE | passive | Base terminal of the NPN transistor; the datasheet gives no base-specific rating beyond the device maximum ratings. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | TO-92 |
| 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 Voltage | VCBO | 300 | V | 1 | |||
| Collector-Emitter Voltage | VCEO | 300 | V | 1 | |||
| Emitter-Base Voltage | VEBO | 5 | V | 1 | |||
| Collector Current - Continuous | IC | 100 | mA | 1 | |||
| Operation Junction and Storage Temperature Range | TJ,Tstg | -55 | 150 | ℃ | 1 | ||
| Thermal resistance from junction to ambient | Rthja | 151 | ℃/W | 1 | |||
| Collector-base breakdown voltage | V(BR)CBO | 300 | V | IC=100μA, IE=0 | 2 | ||
| Collector-emitter breakdown voltage | V(BR)CEO | 300 | V | IC=1mA, IB=0 | 2 | ||
| Emitter-base breakdown voltage | V(BR)EBO | 5 | V | IE=100μA, IC=0 | 2 | ||
| Collector cut-off current | ICBO | 0.01 | μA | VCB=200V, IE=0 | 2 | ||
| Emitter cut-off current | IEBO | 0.05 | μA | VEB=5V, IC=0 | 2 | ||
| DC current gain | hFE | 50 | VCE=20V, IC=25mA | 2 | |||
| Collector-emitter saturation voltage | VCE(sat) | 0.6 | V | IC=30mA, IB=5mA | 2 | ||
| Transition frequency | fT | 60 | MHz | VCE=10V, IC=10mA, f=100MHz | 2 | ||
| Feedback capacitance | Cre | 1.6 | pF | VCE=30V, IC=0, f=1MHz | 2 |
CAD (KiCad official)
- Symbol:
BF420 - Footprint:
Package_TO_SOT_THT:TO-92_Inline - 3D model: TO-92 (KiCad packages3D, STEP)
- 3D model files:
bf420-etched.step/bf420-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bf420.step/bf420.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Changjing datasheet (4 pp, sha256
59caae688fbf914f, 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).