# MM5Z18B

**ST Semtech** · Zener Diodes · SOD-523

MM5Z18B from ST Semtech, in a SOD-523. 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 | Cathode | passive | Cathode terminal of the Zener diode, identified on the package by the cathode line marking. |
| 2 | Anode | passive | Anode terminal of the Zener diode, opposite the cathode line. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ST Semtech |
| Package | SOD-523 |
| Category | Diodes |
| Pins | 2 |

## CAD (KiCad official)

- Symbol: `MM5Z18B`
- Footprint: `Diode_SMD:D_SOD-523`
- 3D model: SOD-523 (KiCad packages3D, STEP)
- 3D model files: `mm5z18b-etched.step` / `mm5z18b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mm5z18b.step` / `mm5z18b.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [ST Semtech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603065798231535616) (4 pp, sha256 `139f9352a078ea9c`, retrieved 2026-10-13, 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/mm5z18b-datasheet.pdf)