component
BC557-TA
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
markdownBC557-TA
Changjing · Bipolar (BJT) · TO-92
BC557-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 | COLLECTOR | passive | Collector of the PNP transistor; the datasheet limits are VCBO -80/-50/-30 V and VCEO -65/-45/-30 V for BC556/BC557/BC558, with continuous collector current of -0.1 A. |
| 2 | BASE | passive | Base of the PNP transistor; the emitter-base voltage is rated at -5 V and the base drives the device with a base current of -0.5 mA to -5 mA in the saturation test conditions. |
| 3 | EMITTER | passive | Emitter of the PNP transistor; the emitter-base breakdown voltage V(BR)EBO is -5 V minimum at IE = -100 µA. |
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 (BC557) | VCBO | -50 | V | 1 | |||
| Collector-emitter voltage (BC557) | VCEO | -45 | V | 1 | |||
| Emitter-base voltage | VEBO | -5 | V | 1 | |||
| Collector current-continuous | IC | -0.1 | A | 1 | |||
| Collector power dissipation | PC | 625 | mW | 1 | |||
| Thermal resistance junction to ambient | RθJA | 200 | ℃/W | 1 | |||
| Operation junction and storage temperature range | TJ,Tstg | -55 | 150 | ℃ | 1 | ||
| Collector-base breakdown voltage (BC557) | V(BR)CBO | -50 | V | IC= -0.1mA,IE=0 | 2 | ||
| Collector-emitter breakdown voltage (BC557) | V(BR)CEO | -45 | V | IC=-2mA,IB=0 | 2 | ||
| Emitter-base breakdown voltage | V(BR)EBO | -5 | V | IE=-100μA,IC=0 | 2 | ||
| Collector cut-off current (BC557) | ICBO | -0.1 | μA | VCB=-45V,IE=0 | 2 | ||
| Emitter cut-off current | IEBO | -0.1 | μA | VEB=-5V,IC=0 | 2 | ||
| DC current gain | hFE | 120 | 800 | VCE=-5V, IC=-2mA | 2 | ||
| Collector-emitter saturation voltage | VCE(sat) | -0.3 | V | IC=-10mA,IB=-0.5mA | 2 | ||
| Collector-emitter saturation voltage | VCE(sat) | -0.65 | V | IC=-100mA,IB=-5mA | 2 | ||
| Base-emitter saturation voltage | VBE(sat) | -0.8 | V | IC=-10mA,IB=-0.5mA | 2 | ||
| Base-emitter saturation voltage | VBE(sat) | -1 | V | IC=-100mA,IB=-5mA | 2 | ||
| Base-emitter voltage | VBE | -0.55 | -0.7 | V | VCE=-5V, IC=-2mA | 2 | |
| Base-emitter voltage | VBE | -0.82 | V | VCE=-5V, IC=-10mA | 2 | ||
| Collector output capacitance | Cob | 6 | pF | VCB=-10V,IE=0, f=1MHz | 2 | ||
| Transition frequency (BC557) | fT | 3150 | MHz | VCE=-5V,IC=-10mA, f=100MHz | 2 |
CAD (KiCad official)
- Symbol:
BC557-TA - Footprint:
Package_TO_SOT_THT:TO-92_Inline - 3D model: TO-92 (KiCad packages3D, STEP)
- 3D model files:
bc557-ta-etched.step/bc557-ta-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bc557-ta.step/bc557-ta.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Changjing datasheet (4 pp, sha256
d56a67b6b9bbd958, 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).