# FZT955

**Changjing** · Bipolar (BJT) · SOT-223

FZT955 from Changjing, in a SOT-223. 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; the datasheet specifies VBE(sat) of -1.11 V max at IC=-3A, IB=-300mA. |
| 2 | COLLECTOR | passive | Collector terminal; the datasheet rates it for a collector current IC of -4 A, collector-emitter voltage VCEO of -140 V and collector power dissipation PC of 0.8 W. |
| 3 | EMITTER | passive | Emitter terminal; the datasheet gives an emitter-base voltage VEBO of -6 V for this device. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-223 |
| 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 | -180 |  |  | V | IC=-0.1mA,IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | -140 |  |  | V | IC=-10mA,IB=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | -6 |  |  | V | IE=-0.1mA,IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | -50 | nA | VCB=-150V,IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | -10 | nA | VEB=-6V,IC=0 | 1 |
| DC current gain hFE(1) | hFE(1) | 100 |  |  |  | VCE=-5V, IC=-10mA | 1 |
| DC current gain hFE(2) | hFE(2) | 100 |  | 300 |  | VCE=-5V, IC=-1A | 1 |
| DC current gain hFE(3) | hFE(3) | 75 |  |  |  | VCE=-5V, IC=-3A | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -60 | mV | IC=-100mA,IB=-5mA | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -120 | mV | IC=-500mA,IB=-50mA | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -150 | mV | IC=-1A,IB=-100mA | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -370 | mV | IC=-3A,IB=-300mA | 1 |
| Base-emitter saturation voltage | VBE(sat) |  |  | -1.11 | V | IC=-3A,IB=-300mA | 1 |
| Base-emitter voltage | VBE |  |  | -0.95 | V | VCE=-5V, IC=-3A | 1 |
| Collector output capacitance | Cob |  |  | 40 | pF | VCB=-20V, IE=0, f=1MHz | 1 |
| Turn-on time | t on |  |  | 68 | ns | VCC=-50V, IC=-1A, IB1=IB2=-100mA | 1 |
| Turn-off time | t off |  |  | 1030 | ns | VCC=-50V, IC=-1A, IB1=IB2=-100mA | 1 |
| Collector-base voltage | VCBO | -180 |  |  | V |  | 1 |
| Collector-emitter voltage | VCEO | -140 |  |  | V |  | 1 |
| Emitter-base voltage | VEBO | -6 |  |  | V |  | 1 |
| Collector current | IC | -4 |  |  | A |  | 1 |
| Collector power dissipation | PC |  |  | 0.8 | W |  | 1 |
| Thermal resistance from junction to ambient | RθJA |  |  | 156 | ℃/W |  | 1 |
| Operation junction and storage temperature range | TJ,Tstg | -55 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `FZT955`
- Footprint: `Package_TO_SOT_SMD:SOT-223-3_TabPin2`
- 3D model: SOT-223 (KiCad packages3D, STEP)
- 3D model files: `fzt955-etched.step` / `fzt955-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `fzt955.step` / `fzt955.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/8590225687216369664) (4 pp, sha256 `572340ab5f9e2f25`, 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/fzt955-datasheet.pdf)