# 2SA940

**Changjing** · Bipolar (BJT) · TO-220

2SA940 from Changjing, in a TO-220. 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; base-emitter voltage VBE is -0.65 V to -0.85 V at VCE=-10 V, IC=-0.5 A, and base drive for VCE(sat) is tested at IB=-50 mA. |
| 2 | COLLECTOR | passive | Collector terminal; limits are VCBO -150 V, VCEO -150 V, continuous IC -1.5 A and collector power dissipation PC 1.5 W. |
| 3 | EMITTER | passive | Emitter terminal; the emitter-base limit is VEBO -5 V and the emitter-base breakdown V(BR)EBO is -5 V minimum at IE=-100 μA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | TO-220 |
| 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 | -150 |  |  | V | IC=-100μA, IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | -150 |  |  | 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 |  |  | -10 | μA | VCB=-120V, IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | -10 | μA | VEB=-5V, IC=0 | 1 |
| DC current gain | hFE | 40 | 140 |  |  | VCE=-10V, IC=-0.5A | 1 |
| Base-emitter voltage | VBE |  | -0.65 | -0.85 | V | VCE=-10V, IC=-0.5A | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -1.5 | V | IC=-0.5A, IB=-50mA | 1 |
| Transition frequency | fT | 4 |  |  | MHz | VCE=-10V, IC=-0.5A | 1 |
| Collector output capacitance | Cob |  |  | 55 | pF | VCB=-10V, IE=0, f=1MHz | 1 |
| Collector-base voltage | VCBO |  |  | -150 | V | Ta=25℃ unless otherwise noted | 1 |
| Collector-emitter voltage | VCEO |  |  | -150 | V | Ta=25℃ unless otherwise noted | 1 |
| Emitter-base voltage | VEBO |  |  | -5 | V | Ta=25℃ unless otherwise noted | 1 |
| Collector current, continuous | IC |  |  | -1.5 | A | Ta=25℃ unless otherwise noted | 1 |
| Collector power dissipation | PC |  |  | 1.5 | W | Ta=25℃ unless otherwise noted | 1 |
| Junction temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage temperature range | Tstg | -55 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `2SA940`
- Footprint: `Package_TO_SOT_THT:TO-220-3_Vertical`
- 3D model: TO-220 (KiCad packages3D, STEP)
- 3D model files: `2sa940-etched.step` / `2sa940-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `2sa940.step` / `2sa940.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/8588895670127742976) (2 pp, sha256 `6bbb477e447ac45c`, 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/2sa940-datasheet.pdf)