# CJ818B

**Changjing** · Bipolar (BJT) · SOT-23-6L

CJ818B from Changjing, in a SOT-23-6L. 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 | C | passive | Collector, tied internally to pins 2, 5 and 6; Vceo -30 V, Ic -3 A continuous. |
| 2 | C | passive | Collector, tied internally to pins 1, 5 and 6; Vceo -30 V, Ic -3 A continuous. |
| 3 | B | passive | Base; Vebo -5 V maximum emitter-base voltage. |
| 4 | E | passive | Emitter of the PNP transistor; Vebo -5 V. |
| 5 | C | passive | Collector, tied internally to pins 1, 2 and 6; Vcbo -30 V. |
| 6 | C | passive | Collector, tied internally to pins 1, 2 and 5; Vcbo -30 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-23-6L |
| Category | Transistors/Thyristors |
| Pins | 6 |

## 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 | -30 |  |  | V | IC=-100μA,IE=0 | 2 |
| Collector-emitter breakdown voltage | V(BR)CEO | -30 |  |  | V | IC=-10mA,IB=0 | 2 |
| Emitter-base breakdown voltage | V(BR)EBO | -5 |  |  | V | IE=-100μA,IC=0 | 2 |
| Collector cut-off current | ICBO |  |  | -0.1 | μA | VCB=-30V,IE=0 | 2 |
| Emitter cut-off current | IEBO |  |  | -0.1 | μA | VEB=-5V,IC=0 | 2 |
| DC current gain | hFE | 100 |  |  |  | VCE=-1V, IC=-0.5A | 2 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -0.15 | V | IC=-0.5A,IB=-5mA | 2 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -0.45 | V | IC=-1.2A,IB=-12mA | 2 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -0.8 | V | IC=-2A,IB=-20mA | 2 |
| Base-emitter saturation voltage | VBE(sat) |  |  | -1.1 | V | IC=-0.5A,IB=-5mA | 2 |
| Base-emitter saturation voltage | VBE(sat) |  |  | -1.2 | V | IC=-2A,IB=-20mA | 2 |
| Base-emitter on voltage | VBE(on) |  |  | -1.1 | V | IC=-0.5A, VCE=-2V | 2 |
| Collector-base voltage (maximum rating) | VCBO |  |  | -30 | V |  | 1 |
| Collector-emitter voltage (maximum rating) | VCEO |  |  | -30 | V |  | 1 |
| Emitter-base voltage (maximum rating) | VEBO |  |  | -5 | V |  | 1 |
| Collector current, continuous | IC |  |  | -3 | A | Continuous | 1 |
| Collector dissipation | PC |  |  | 0.35 | W |  | 1 |
| Total dissipation | Ptot |  |  | 1.2 | W | TC = 25℃ | 1 |
| Operation junction and storage temperature range | TJ,Tstg | -55 |  | 150 | ℃ |  | 1 |
| Thermal resistance, junction to ambient | RθJA |  | 357 |  | ℃/W |  | 1 |
| Thermal resistance, junction to case | RθJC |  | 104.2 |  | ℃/W | Package mounted on FR4 pcb 25mm x 25mm (note 1) | 1 |

## CAD (KiCad official)

- Symbol: `CJ818B`
- Footprint: `Package_TO_SOT_SMD:SOT-23-6`
- 3D model: SOT-23-6L (KiCad packages3D, STEP)
- 3D model files: `cj818b-etched.step` / `cj818b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `cj818b.step` / `cj818b.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Changjing datasheet](docs/cj818b-datasheet.pdf) (5 pp, sha256 `ddb191db125b5795`, retrieved 2026-10-17, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-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/cj818b-datasheet.pdf)