# 2SA1037

**Changjing** · Bipolar (BJT) · SOT-23

2SA1037 from Changjing, in a SOT-23. 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, with emitter-base voltage limited to VEBO = -6 V and the base-driven saturation test specified at IC = -50 mA, IB = -5 mA. |
| 2 | EMITTER | passive | Emitter terminal, rated for emitter-base voltage VEBO = -6 V with emitter-base breakdown V(BR)EBO of -6 V at IE = -50 μA. |
| 3 | COLLECTOR | passive | Collector terminal, rated for collector-base voltage VCBO = -60 V, collector-emitter voltage VCEO = -50 V, continuous collector current IC = -150 mA, and collector power dissipation PC = 200 mW. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-23 |
| 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=-50μA,IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | -50 |  |  | V | IC=-1mA,IB=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | -6 |  |  | V | IE=-50μA,IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | -0.1 | μA | VCB=-60V,IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | -0.1 | μA | VEB=-6V,IC=0 | 1 |
| DC current gain | hFE | 120 |  | 560 |  | VCE=-6V,IC=-1mA | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -0.5 | V | IC=-50mA,IB=-5mA | 1 |
| Transition frequency | fT | 140 |  |  | MHz | VCE=-12V,IC=-2mA,f=30MHz | 1 |
| Collector output capacitance | Cob |  | 4 | 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 |  |  | 200 | mW |  | 1 |
| Junction temperature | TJ |  |  | 150 | ℃ |  | 1 |
| Storage temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `2SA1037`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `2sa1037-etched.step` / `2sa1037-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `2sa1037.step` / `2sa1037.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/8586172911971405824) (2 pp, sha256 `c17ad5d84e9475e9`, retrieved 2026-10-18, 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/2sa1037-datasheet.pdf)