# CZT127

**Changjing** · Darlington Transistors · SOT-223

CZT127 from Changjing, in a SOT-223. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | B | input | Base of the PNP Darlington transistor. VEBO max = -5 V. Drive current sets collector current via combined Darlington gain (hFE ≥ 1000 typical at IC = -3 A, VCE = -3 V). |
| 2 | C | passive | Collector of the PNP Darlington transistor. VCBO max = -100 V, VCEO max = -100 V, IC(continuous) = -5 A, PC = 1 W. Tab (large center pad) of the SOT-223 is internally connected to the collector. |
| 3 | E | passive | Emitter of the PNP Darlington transistor. VBE(on) ≈ -2.5 V at IC = -3 A (two Vbe drops due to Darlington). VCE(sat) ≤ -2 V at IC = -3 A, IB = -12 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-223 |
| Category | Transistors/Thyristors |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `CZT127`
- Footprint: `Package_TO_SOT_SMD:SOT-223-3_TabPin2`
- 3D model: SOT-223 (KiCad packages3D, STEP)
- 3D model files: `czt127-etched.step` / `czt127-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `czt127.step` / `czt127.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/8586181803367944192) (3 pp, sha256 `f209bc4fcfb6864a`, retrieved 2026-08-17, tier: lcsc)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/czt127-datasheet.pdf)