component
BF422
Public Made by Adomby adom
Changjing Bipolar Transistors - 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
markdownBF422
Changjing · Bipolar Transistors - BJT · TO-92
BF422 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 of the NPN transistor; emitter-base voltage limited to 5 V (VEBO) and V(BR)EBO min 5 V at IE=100 µA. |
| 2 | COLLECTOR | passive | Collector of the NPN transistor; BF422 VCBO/VCEO 250 V, continuous collector current 100 mA. |
| 3 | BASE | passive | Base of the NPN transistor; drives the device with VCE(sat) max 0.6 V at IC=30 mA, IB=5 mA. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | TO-92 |
| Category | Triode/MOS Tube/Transistor |
| 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 | 250 | V | Ta=25℃ | 1 | ||
| Collector-Emitter Voltage | VCEO | 250 | V | Ta=25℃ | 1 | ||
| Emitter-Base Voltage | VEBO | 5 | V | Ta=25℃ | 1 | ||
| Collector Current - Continuous | IC | 100 | mA | Ta=25℃ | 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 | 250 | V | IC=100μA, IE=0 | 2 | ||
| Collector-emitter breakdown voltage | V(BR)CEO | 250 | 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:
BF422 - Footprint:
Package_TO_SOT_THT:TO-92_Inline - 3D model: TO-92 (KiCad packages3D, STEP)
- 3D model files:
bf422-etched.step/bf422-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bf422.step/bf422.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Changjing datasheet (4 pp, sha256
d40fa16eef2f6380, retrieved 2026-10-23, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-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).