# 2SA1579

**Changjing** · Bipolar (BJT) · SOT-323

2SA1579 from Changjing, 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 PNP transistor; the datasheet gives no pin-specific limit, and the device-level ratings apply (VEBO -5 V, IC -50 mA, PC 100 mW, Tj/Tstg -55 to +150 ℃). |
| 2 | EMITTER | passive | Emitter terminal of the PNP transistor; the datasheet gives no pin-specific limit, and the device-level ratings apply (VEBO -5 V, IC -50 mA, PC 100 mW, Tj/Tstg -55 to +150 ℃). |
| 3 | COLLECTOR | passive | Collector terminal of the PNP transistor; the datasheet gives no pin-specific limit, and the device-level ratings apply (VCBO -120 V, VCEO -120 V, IC -50 mA, PC 100 mW). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| 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 | -120 |  |  | V | IC=-50μA,IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | -120 |  |  | V | IC=-1mA,IB=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | -5 |  |  | V | IE=-50μA,IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | -0.5 | μA | VCB=-100V,IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | -0.5 | μA | VEB=-4V,IC=0 | 1 |
| DC current gain | hFE | 180 |  | 560 |  | VCE=-6V,IC=-2mA | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -0.5 | V | IC=-10mA,IB=-1mA | 1 |
| Transition frequency | fT | 140 |  |  | MHz | VCE=-12V,IC=-2mA,f=30MHz | 1 |
| Collector output capacitance | Cob |  |  | 3.2 | pF | VCB=-12V,IE=0,f=1MHz | 1 |
| Collector-Base Voltage | VCBO |  |  | -120 | V | Ta=25℃ unless otherwise noted | 1 |
| Collector-Emitter Voltage | VCEO |  |  | -120 | V | Ta=25℃ unless otherwise noted | 1 |
| Emitter-Base Voltage | VEBO |  |  | -5 | V | Ta=25℃ unless otherwise noted | 1 |
| Collector Current | IC |  |  | -50 | mA | Ta=25℃ unless otherwise noted | 1 |
| Collector Power Dissipation | PC |  |  | 100 | mW | Ta=25℃ unless otherwise noted | 1 |
| Thermal Resistance From Junction To Ambient | RΘJA |  |  | 1250 | ℃/W | Ta=25℃ unless otherwise noted | 1 |
| Operation Junction and Storage Temperature Range | TJ,Tstg | -55 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `2SA1579`
- Footprint: `Package_TO_SOT_SMD:SOT-323_SC-70`
- 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files: `2sa1579-etched.step` / `2sa1579-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `2sa1579.step` / `2sa1579.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/8603345750873026560) (4 pp, sha256 `a35eeb2aab7418b8`, retrieved 2026-10-17, 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/2sa1579-datasheet.pdf)