# CJ7908

**Changjing** · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · TO-252-2(DPAK)

CJ7908 from Changjing, in a TO-252-2(DPAK). 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 for the CJ7908 negative regulator, with typical quiescent current of 1.5 mA (2 mA max) at TJ=25°C. |
| 2 | IN | power_in | Negative unregulated input voltage Vi (-35 V appears as the input rating, -14 V test condition), decoupled with a 2.2 µF input capacitor Ci. |
| 3 | OUT | power_out | Regulated -8 V output (-7.76 V to -8.24 V at TJ=25°C, 1.5 A maximum output current), with a 1 µF output capacitor Co. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | TO-252-2(DPAK) |
| 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 | Vo | -7.6 | -8 | -8.4 | V | TJ=25℃; -10.5V≤Vi≤-23V, Io=5mA-1A | 1 |
| Output Voltage | Vo | -7.76 | -8 | -8.24 | V | Ta= 25 ℃ | 1 |
| Load Regulation | ∆Vo |  | 15 | 160 | mV | TJ=25℃; Io=5mA-1.5A | 1 |
| Load Regulation | ∆Vo |  | 5 | 80 | mV | TJ=25℃; Io=250mA-750mA | 1 |
| Line Regulation | ∆Vo |  | 12.5 | 160 | mV | TJ=25℃; -10.5V≤Vi≤-25V | 1 |
| Line Regulation | ∆Vo |  | 4 | 80 | mV | TJ=25℃; -11V≤Vi≤-17V | 1 |
| Quiescent Current | Iq |  | 1.5 | 2 | mA | TJ=25℃ | 1 |
| Ripple Rejection | RR | 54 | 60 |  | dB | TJ=25℃; -11.5V≤Vi≤-21.5V, f=120Hz | 1 |
| Operating Junction Temperature Range | TOPR | -40 |  | 125 | ℃ | Operating temperature range applies unless otherwise specified | 1 |
| Storage Temperature Range | TSTG | -65 |  | 150 | ℃ |  | 1 |
| Continuous Total Dissipation | PD |  |  | 1.25 | W |  | 1 |
| Maximum Output Current | IOM |  |  | 1.5 | A |  | 1 |
| Quiescent Current Change | ∆Iq |  | 1 |  | mA | TJ=25℃; -10.5V≤Vi≤-25V | 1 |
| Quiescent Current Change | ∆Iq |  | 0.5 |  | mA | TJ=25℃; 5mA≤IO≤1A | 1 |
| Output Noise Voltage | VN |  | 200 |  | μV | 10Hz≤f≤100KHz | 1 |
| Output Voltage Drift | △Vo/△T |  | -0.6 |  | mV/℃ | IO=5mA | 1 |
| Dropout Voltage | Vd |  | 1.1 |  | V | Io=1A | 1 |
| Peak Current | Ipk |  | 2.1 |  | A |  | 1 |
| Thermal Resistance from Junction to Air | RθJA |  | 100 |  | ℃/W |  | 1 |

## CAD (KiCad official)

- Symbol: `CJ7908`
- Footprint: `Package_TO_SOT_SMD:TO-252-2`
- 3D model: TO-252-2(DPAK) (KiCad packages3D, STEP)
- 3D model files: `cj7908-etched.step` / `cj7908-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `cj7908.step` / `cj7908.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/8586203170297024512) (3 pp, sha256 `f68e9d1c63c3cf7c`, 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/cj7908-datasheet.pdf)