component
BC637-TA
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Changjing Bipolar (BJT), TO-92. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
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BC637-TA
Changjing · Bipolar (BJT) · TO-92
BC637-TA 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; the datasheet rates emitter-base voltage VEBO at 5 V. |
| 2 | COLLECTOR | passive | Collector terminal; for BC637 the collector-emitter voltage VCEO is 60 V and continuous collector current IC is 1 A, with collector power dissipation PC of 0.83 W. |
| 3 | BASE | passive | Base terminal of the NPN transistor; the saturation test condition is IC=500 mA with IB=50 mA (VCE(sat) 0.5 V max). |
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-Emitter Voltage (VCBO), BC637 | VCBO | 60 | V | 1 | |||
| Collector-Emitter Voltage (VCEO), BC637 | VCEO | 60 | V | 1 | |||
| Emitter-Base Voltage | VEBO | 5 | V | 1 | |||
| Collector Current - Continuous | IC | 1 | A | 1 | |||
| Collector Power Dissipation | PC | 0.83 | W | Ta=25℃ | 1 | ||
| Operation Junction and Storage Temperature Range | TJ,Tstg | -55 | 150 | ℃ | 1 | ||
| Collector-emitter breakdown voltage, BC637 | V(BR)CEO | 60 | V | IC=10mA, IB=0 | 2 | ||
| Collector cut-off current | ICBO | 0.1 | μA | VCB=30 V, IE=0 | 2 | ||
| Emitter cut-off current | IEBO | 0.1 | μA | VEB=5V, IB=0 | 2 | ||
| DC current gain hFE(1) | hFE(1) | 25 | VCE=2 V, IC=5mA | 2 | |||
| DC current gain hFE(3) | hFE(3) | 25 | VCE=2V, IC=500mA | 2 | |||
| Collector-emitter saturation voltage | VCE(sat) | 0.5 | V | IC=500mA, IB=50mA | 2 | ||
| Base-emitter voltage | VBE | 1 | V | VCE=2V, IC=500mA | 2 | ||
| Transition frequency | fT | 100 | MHz | VCE=5V, IC=10mA, f=50 MHZ | 2 |
CAD (KiCad official)
- Symbol:
BC637-TA - Footprint:
Package_TO_SOT_THT:TO-92_Inline - 3D model: TO-92 (KiCad packages3D, STEP)
- 3D model files:
bc637-ta-etched.step/bc637-ta-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bc637-ta.step/bc637-ta.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Changjing datasheet (5 pp, sha256
52e4f6f4f4a84afe, retrieved 2026-10-18, 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).
# BC637-TA
**Changjing** · Bipolar (BJT) · TO-92
BC637-TA 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; the datasheet rates emitter-base voltage VEBO at 5 V. |
| 2 | COLLECTOR | passive | Collector terminal; for BC637 the collector-emitter voltage VCEO is 60 V and continuous collector current IC is 1 A, with collector power dissipation PC of 0.83 W. |
| 3 | BASE | passive | Base terminal of the NPN transistor; the saturation test condition is IC=500 mA with IB=50 mA (VCE(sat) 0.5 V max). |
## 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-Emitter Voltage (VCBO), BC637 | VCBO | | | 60 | V | | 1 |
| Collector-Emitter Voltage (VCEO), BC637 | VCEO | | | 60 | V | | 1 |
| Emitter-Base Voltage | VEBO | | | 5 | V | | 1 |
| Collector Current - Continuous | IC | | | 1 | A | | 1 |
| Collector Power Dissipation | PC | | | 0.83 | W | Ta=25℃ | 1 |
| Operation Junction and Storage Temperature Range | TJ,Tstg | -55 | | 150 | ℃ | | 1 |
| Collector-emitter breakdown voltage, BC637 | V(BR)CEO | 60 | | | V | IC=10mA, IB=0 | 2 |
| Collector cut-off current | ICBO | | | 0.1 | μA | VCB=30 V, IE=0 | 2 |
| Emitter cut-off current | IEBO | | | 0.1 | μA | VEB=5V, IB=0 | 2 |
| DC current gain hFE(1) | hFE(1) | 25 | | | | VCE=2 V, IC=5mA | 2 |
| DC current gain hFE(3) | hFE(3) | 25 | | | | VCE=2V, IC=500mA | 2 |
| Collector-emitter saturation voltage | VCE(sat) | | | 0.5 | V | IC=500mA, IB=50mA | 2 |
| Base-emitter voltage | VBE | | | 1 | V | VCE=2V, IC=500mA | 2 |
| Transition frequency | fT | | 100 | | MHz | VCE=5V, IC=10mA, f=50 MHZ | 2 |
## CAD (KiCad official)
- Symbol: `BC637-TA`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92 (KiCad packages3D, STEP)
- 3D model files: `bc637-ta-etched.step` / `bc637-ta-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bc637-ta.step` / `bc637-ta.glb` are the bare package body.
## Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- **Datasheet:** [Changjing datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590226985407983616) (5 pp, sha256 `52e4f6f4f4a84afe`, retrieved 2026-10-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-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).
[Datasheet PDF](docs/bc637-ta-datasheet.pdf)