# 2SA1774

**Changjing** · Bipolar (BJT) · SOT-523

2SA1774 from Changjing, in a SOT-523. 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 | Base terminal of the PNP transistor, driven with IB=-5.0 mA in the datasheet's saturation test at IC=-50 mA; emitter-base voltage is rated at VEBO -6 V. |
| 2 | EMITTER | passive | Emitter terminal of the PNP transistor; the datasheet lists the emitter-base breakdown voltage V(BR)EBO as -6.0 V minimum at IE=-50 µA and the absolute maximum emitter-base voltage as -6 V. |
| 3 | COLLECTOR | passive | Collector terminal of the PNP transistor; rated at -60 V collector-base (VCBO) and -50 V collector-emitter (VCEO), with -150 mA continuous collector current and 150 mW collector power dissipation. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-523 |
| 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 |
|---|---|---|---|---|---|---|---|
| DC current gain (hFE rank range, Q/R/S) | hFE(1) | 120 |  | 560 |  | VCE=-6.0V, IC=-1.0mA | 1 |
| Collector-base breakdown voltage | V(BR)CBO | -60 |  |  | V | IC=-50uA, IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | -50 |  |  | V | IC=-1.0mA, IB=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | -6 |  |  | V | IE=-50μA, IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | -0.1 | uA | VCB=-60V, IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | -0.1 | μA | VEB=-6V, IC=0 | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -0.5 | V | IC=-50mA, IB=-5.0mA; pulse test PW≤300us, D.C≤2% | 1 |
| Base-emitter saturation voltage | VBE(sat) |  |  | -1.2 | V | IC=-50mA, IB=-5.0mA; pulse test PW≤300us, D.C≤2% | 1 |
| Transition frequency | fT |  | 140 |  | MHz | VCE=-12V, IC=-2.0mA, f=30MHZ | 1 |
| Collector output capacitance | Cob |  | 3.5 | 5 | pF | VCB=-12V, IE=0, f=1MHz | 1 |
| Collector-base voltage | VCBO |  |  | -60 | V |  | 1 |
| Collector-emitter voltage | VCEO |  |  | -50 | V |  | 1 |
| Emitter-base voltage | VEBO |  |  | -6 | V |  | 1 |
| Collector current, continuous | IC |  |  | -150 | mA |  | 1 |
| Collector power dissipation | PC |  |  | 150 | mW |  | 1 |
| Operation junction and storage temperature range | TJ,Tstg | -55 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `2SA1774`
- Footprint: `Package_TO_SOT_SMD:SOT-523`
- 3D model: SOT-523, generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 0.8 mm nominal SOT-523 height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
- 3D model files: `2sa1774-etched.step` / `2sa1774-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `2sa1774.step` / `2sa1774.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/8590237190002409472) (4 pp, sha256 `a4f334fa3e0f6afb`, 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/2sa1774-datasheet.pdf)