# 2SC4548

**Changjing** · Bipolar (BJT) · SOT-89-3L

2SC4548 from Changjing, in a SOT-89-3L. 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 | input | NPN transistor base terminal; the emitter-base breakdown voltage V(BR)EBO is 5 V minimum at IE=10µA, and VBE(sat) is 1 V max at IC=50mA, IB=5mA. |
| 2 | COLLECTOR | passive | NPN transistor collector terminal; limited to 400 V VCBO and 400 V VCEO, 200 mA collector current IC, and 500 mW collector power dissipation PC. |
| 3 | EMITTER | passive | NPN transistor emitter terminal; the emitter-base voltage rating VEBO is 5 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-89-3L |
| 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 | 400 |  |  | V | IC=10µA,IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | 400 |  |  | V | IC=1mA,IB=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | 5 |  |  | V | IE=10µA,IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | 0.1 | µA | VCB=300V,IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | 0.1 | µA | VEB=4V,IC=0 | 1 |
| DC current gain | hFE | 60 |  | 200 |  | VCE=10V, IC=50mA | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | 0.6 | V | IC=50mA,IB=5mA | 1 |
| Base-emitter saturation voltage | VBE(sat) |  |  | 1 | V | IC=50mA,IB=5mA | 1 |
| Transition frequency | fT | 70 |  |  | MHz | VCE=30V,IC=10mA | 1 |
| Collector output capacitance | Cob |  |  | 4 | pF | VCB=30V, IE=0, f=1MHz | 1 |
| Collector-Base Voltage | VCBO |  |  | 400 | V |  | 1 |
| Collector-Emitter Voltage | VCEO |  |  | 400 | V |  | 1 |
| Emitter-Base Voltage | VEBO |  |  | 5 | V |  | 1 |
| Collector Current | IC |  |  | 200 | mA |  | 1 |
| Collector Power Dissipation | PC |  |  | 500 | mW |  | 1 |
| Junction Temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage Temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Thermal Resistance From Junction To Ambient | RθJA |  |  | 250 | ℃/W |  | 1 |

## CAD (KiCad official)

- Symbol: `2SC4548`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89-3L (KiCad packages3D, STEP)
- 3D model files: `2sc4548-etched.step` / `2sc4548-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `2sc4548.step` / `2sc4548.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/8586174749394919424) (1 pp, sha256 `3b3f66e62d088c7e`, retrieved 2026-10-20, 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/2sc4548-datasheet.pdf)