# MMSZ4712

**Changjing** · Zener Diodes · SOD-123

MMSZ4712 from Changjing, in a SOD-123. 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 | K | passive | Cathode, the end of the SOD-123 body with the marking band (labelled "-" on the package drawing), which is the reverse zener voltage side of the diode symbol. |
| 2 | A | passive | Anode, the end of the SOD-123 body without the marking band (labelled "+" on the package drawing). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOD-123 |
| Category | Diodes |
| Pins | 2 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Power Dissipation | PD |  |  | 500 | mW | Mounted on 1 in2 FR-4 board with 2oz copper, still air, Ta=25 ℃ (note 1) | 1 |
| Forward voltage | VF |  |  | 0.9 | V | @ IF=10mA, tested with pulses Tp≤1.0ms (note 2) | 1 |
| Operating Junction and Storage Temperature Range | TJ,Tstg | -55 |  | 150 | ℃ |  | 1 |
| Thermal Resistance, Junction to Ambient Air | RθJA |  | 250 |  | ℃/W |  | 1 |

## CAD (KiCad official)

- Symbol: `MMSZ4712`
- Footprint: `Diode_SMD:D_SOD-123F`
- 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files: `mmsz4712-etched.step` / `mmsz4712-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mmsz4712.step` / `mmsz4712.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/8590922112909451264) (4 pp, sha256 `68ead5ee34de6d65`, retrieved 2026-10-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-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/mmsz4712-datasheet.pdf)