# 2SC4177

**TWGMC** · Bipolar (BJT) · SOT-323

2SC4177 from TWGMC, in a SOT-323. 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 | BASE | passive | Base terminal of the NPN transistor, rated with emitter-base voltage VEBO of 5 V maximum and a base-emitter saturation voltage of 1 V maximum at IC=100 mA, IB=10 mA. |
| 2 | EMITTER | passive | Emitter terminal of the NPN transistor, with emitter-base breakdown voltage V(BR)EBO of 5 V at IE=100 µA. |
| 3 | COLLECTOR | passive | Collector terminal of the NPN transistor, rated at collector-emitter voltage VCEO of 50 V, collector-base voltage VCBO of 60 V and collector current IC of 100 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | TWGMC |
| Package | SOT-323 |
| 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 breakdown voltage | V(BR)CBO | 60 |  |  | V | IC=100µA, IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | 50 |  |  | V | IC=1mA, IB=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | 5 |  |  | V | IE=100µA, IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | 100 | nA | VCB=60V, IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | 100 | nA | VEB=5V, IC=0 | 1 |
| DC current gain | hFE | 90 |  | 600 |  | VCE=6V, IC=1mA | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | 0.3 | V | IC=100mA, IB=10mA | 1 |
| Base-emitter saturation voltage | VBE(sat) |  |  | 1 | V | IC=100mA, IB=10mA | 1 |
| Base-emitter voltage | VBE | 0.55 |  | 0.65 | V | VCE=6V, IC=1mA | 1 |
| Transition frequency | fT | 250 |  |  | MHz | VCE=6V, IC=10mA | 1 |
| Collector output capacitance | Cob |  |  | 3 | pF | VCB=6V, IE=0, f=1MHz | 1 |
| Collector-base voltage | VCBO |  |  | 60 | V |  | 1 |
| Collector-emitter voltage | VCEO |  |  | 50 | V |  | 1 |
| Emitter-base voltage | VEBO |  |  | 5 | V |  | 1 |
| Collector current | IC |  |  | 100 | mA |  | 1 |
| Collector power dissipation | PC |  |  | 150 | mW |  | 1 |
| Junction temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Thermal resistance, junction to ambient | RθJA |  |  | 833 | ℃/W |  | 1 |

## CAD (KiCad official)

- Symbol: `2SC4177`
- Footprint: `Package_TO_SOT_SMD:SOT-323_SC-70`
- 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files: `2sc4177-etched.step` / `2sc4177-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `2sc4177.step` / `2sc4177.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [TWGMC datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590458757236371456) (3 pp, sha256 `2e7c4cf49dd2b338`, retrieved 2026-10-09, 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/2sc4177-datasheet.pdf)