# CJ79L09

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

CJ79L09 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 of the negative three-terminal regulator; the datasheet gives no electrical limits for this pin. |
| 2 | IN | power_in | Unregulated negative input voltage with an absolute maximum of -30 V; bypass with a 0.33 μF input capacitor close to the regulator. |
| 3 | OUT | power_out | Regulated negative output of -9 V (typical) with a maximum output current of 0.1 A; bypass with a 0.1 μF output capacitor close to the regulator. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-89-3L |
| Category | Power Management (PMIC) |
| 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 |
|---|---|---|---|---|---|---|---|
| Output Voltage (25℃) | Vo | -8.64 | -9 | -9.36 | V | 25℃ | 1 |
| Output Voltage (line/load range) | Vo | -8.55 | -9 | -9.45 | V | -12V≤Vl≤-24V, Io=1mA-40mA | 1 |
| Output Voltage (full load, temperature range) | Vo | -8.55 | -9 | -9.45 | V | Io=1mA-70mA, 0-125℃ | 1 |
| Load Regulation | ΔVo |  | 19 | 90 | mV | Io=1mA-100mA, 25℃ | 1 |
| Load Regulation | ΔVo |  | 11 | 40 | mV | Io=1mA-40mA, 25℃ | 1 |
| Line Regulation | ΔVo |  | 45 | 175 | mV | -12V≤Vl≤-24V, 25℃ | 1 |
| Line Regulation | ΔVo |  | 40 | 125 | mV | -13V≤Vl≤-24V, 25℃ | 1 |
| Quiescent Current | Iq |  | 4.1 | 6 | mA | 25℃ | 1 |
| Quiescent Current Change (line) | ΔIq |  |  | 1.5 | mA | -13V≤Vl≤-24V, 0-125℃ | 1 |
| Quiescent Current Change (load) | ΔIq |  |  | 0.1 | mA | 1mA≤Vl≤40mA, 0-125℃ | 1 |
| Ripple Rejection | RR | 45 |  |  | dB | -15V≤Vl≤-24V, f=120Hz, 0-125℃ | 1 |
| Input Voltage | Vl |  |  | -30 | V |  | 1 |
| Operating Junction Temperature Range | TOPR | 0 |  | 150 | ℃ |  | 1 |
| Storage Temperature Range | TSTG | -55 |  | 150 | ℃ |  | 1 |
| Maximum Output Current | IOM |  |  | 0.1 | A |  | 1 |
| Continuous Total Dissipation | PD |  |  | 0.5 | W |  | 1 |

## CAD (KiCad official)

- Symbol: `CJ79L09`
- Footprint: `Package_TO_SOT_SMD:SOT-89-3`
- 3D model: SOT-89-3L (KiCad packages3D, STEP)
- 3D model files: `cj79l09-etched.step` / `cj79l09-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `cj79l09.step` / `cj79l09.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/8586171912854097920) (1 pp, sha256 `df89945388d061e5`, retrieved 2026-10-18, 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/cj79l09-datasheet.pdf)