# CJ432

**Changjing** · Voltage Reference · SOT-23

CJ432 from Changjing, in a SOT-23. 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 | REF | input | Reference input pin. Voltage on this pin (1.2214-1.2586V, typ 1.24V) is compared internally against the bandgap reference; regulates the shunt when Vref threshold is exceeded. Reference input current is on the order of hundreds of nA (max 6μA over range). |
| 2 | CATHODE | passive | Cathode (K) of the shunt regulator. Sinks current from the load when Vref exceeds the internal bandgap. Max continuous cathode current 100mA, max cathode voltage 18V, dynamic impedance 0.5Ω typ. |
| 3 | ANODE | passive | Anode (A) of the shunt regulator. Normally tied to circuit ground / low-side return; forms the current return path for the shunt element. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-23 |
| Category | 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 |
|---|---|---|---|---|---|---|---|
| Reference input voltage | Vref | 1.2214 |  | 1.2586 | V | VKA=VREF, IKA=10mA (Fig 1) | 2 |
| Deviation of reference voltage over full temperature range | △Vref(DEV) |  |  | 16 | mV | VKA=VREF, IKA=10mA, 0℃≤Ta≤70℃ (Fig 1) | 2 |
| Ratio of change in reference input voltage to change in cathode voltage | △Vref / △VKA |  |  | 2.4 | mV/V | IKA=10mA, △VKA=1.25V~15V (Fig 2) | 2 |
| Deviation of reference input current over full temperature range | △Iref / △T |  |  | 0.6 | μA | IKA=10mA, R1=10kΩ, R2=∞, 0℃≤Ta≤70℃ (Fig 2) | 2 |
| Minimum cathode current for regulation | IKA(min) | 0.1 |  |  | mA | VKA=VREF | 2 |
| Off-state cathode current | Ioff |  |  | 0.5 | μA | VKA=15V, VREF=0 (Fig 3) | 2 |
| Dynamic impedance | ZKA |  |  | 0.5 | Ω | VKA=VREF, IKA=0.1~20mA, f≤1.0kHz | 2 |
| Cathode Voltage | VKA |  |  | 18 | V |  | 1 |
| Cathode Current Range (continuous) | IKA |  |  | 100 | mA | continuous | 1 |
| Reference Input Current Range | Iref |  |  | 6 | μA |  | 1 |
| Power Dissipation | PD |  |  | 350 | mW |  | 1 |
| Thermal Resistance from Junction to Ambient | RθJA |  |  | 357 | ℃/W |  | 1 |
| Operating Junction Temperature Range | TJ | -40 |  | 125 | ℃ |  | 1 |
| Storage Temperature Range | Tstg | -65 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `CJ432`
- Footprint: `Package_TO_SOT_SMD:SOT-23`
- 3D model: SOT-23 (KiCad packages3D, STEP)
- 3D model files: `cj432-etched.step` / `cj432-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `cj432.step` / `cj432.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`cj432.step`](cj432.step) | 59 KB | You want the bare part, or you mark your own boards. |
| [`cj432-etched.step`](cj432-etched.step) | 1.1 MB | You want the part with `CJ432` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 268 faces against 69 in the bare model. It
survives export, section views, and rendering in any CAD tool, and it drops straight
into KiCad or Fusion with no extra setup.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Changjing datasheet](docs/cj432-datasheet.pdf) (7 pp, sha256 `6ff031d80f2f1bfd`, 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/cj432-datasheet.pdf)