# CJ7550S

**Changjing** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOT-89-3L

CJ7550S from Changjing, in a SOT-89-3L. 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 | GND | power_in | Ground reference pin for the regulator; all datasheet voltage limits are referenced to this network ground terminal. |
| 2 | IN | power_in | Input supply pin with a recommended supply range of 2.5V to 36V and an absolute maximum of -0.3V to 40V, with a 1µF input capacitor recommended for stability. |
| 3 | OUT | power_out | Regulated 5.0V output for the CJ7550S that delivers up to 300mA, with a 1µF output capacitor recommended and an absolute maximum output voltage of -0.3V to 13V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-89-3L |
| Category | Power Management (PMIC) |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `CJ7550S`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89-3L (KiCad packages3D, STEP)
- 3D model files: `cj7550s-etched.step` / `cj7550s-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `cj7550s.step` / `cj7550s.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/8589837714662330369) (7 pp, sha256 `a788f7aff9aef4d9`, retrieved 2026-10-09, 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/cj7550s-datasheet.pdf)