# 8550SS-TA

**Changjing** · Bipolar (BJT) · TO-92-3

8550SS-TA from Changjing, in a TO-92-3. 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 | EMITTER | passive | Emitter terminal of the PNP transistor; the datasheet limits the emitter-base voltage to -5 V (VEBO). |
| 2 | COLLECTOR | passive | Collector terminal of the PNP transistor; the datasheet limits continuous collector current to -1.5 A, collector-base voltage to -40 V (VCBO), and collector power dissipation to 1 W. |
| 3 | BASE | passive | Base terminal of the PNP transistor; the datasheet gives VBE(sat) of -1.2 V at IC=-800 mA, IB=-80 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | TO-92-3 |
| 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-emitter saturation voltage | VCE(sat) |  |  | -0.5 | V | IC=-800mA,IB=-80mA | 1 |
| Base-emitter saturation voltage | VBE(sat) |  |  | -1.2 | V | IC=-800mA,IB=-80mA | 1 |
| DC current gain hFE(1) | hFE(1) | 85 |  | 300 |  | VCE=-1, IC=-100mA | 1 |
| DC current gain hFE(2) | hFE(2) | 40 |  |  |  | VCE=-1V, IC=-800mA | 1 |
| Transition frequency | fT | 100 |  |  | MHz | VCE=-10V,IC=-50mA,f=30MHz | 1 |
| Collector-base breakdown voltage | V(BR)CBO | -40 |  |  | V | IC= -0.1mA,IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | -25 |  |  | V | IC=-0.1mA,IB=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | -5 |  |  | V | IE=-0.1mA,IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | -0.1 | μA | VCB=-40V,IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | -0.1 | μA | VEB=-5V,IC=0 | 1 |
| Collector-base voltage | VCBO |  |  | -40 | V |  | 1 |
| Collector-emitter voltage | VCEO |  |  | -25 | V |  | 1 |
| Emitter-base voltage | VEBO |  |  | -5 | V |  | 1 |
| Collector current, continuous | IC |  |  | -1.5 | A | Continuous | 1 |
| Collector power dissipation | PC |  |  | 1 | W |  | 1 |
| Junction temperature | Tj |  |  | 150 | ℃ |  | 1 |
| Storage temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |
| Thermal resistance, junction to ambient | RθJA |  | 125 |  | ℃/W |  | 1 |

## CAD (KiCad official)

- Symbol: `8550SS-TA`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92-3 (KiCad packages3D, STEP)
- 3D model files: `8550ss-ta-etched.step` / `8550ss-ta-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `8550ss-ta.step` / `8550ss-ta.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/8588895097093541888) (2 pp, sha256 `719b36a5f64af94c`, retrieved 2026-10-19, 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/8550ss-ta-datasheet.pdf)