# MM1Z5B1

**ST Semtech** · Zener Diodes · SOD-123

MM1Z5B1 from ST Semtech, 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 | Cathode | passive | Cathode of the zener diode; for the MM1Z5B1 (5.1 V type) the zener voltage range is 4.998 V to 5.202 V at IZT = 5 mA, with reverse leakage IR of 2 µA max at VR = 1.5 V. |
| 2 | Anode | passive | Anode of the zener diode; forward voltage VF is 0.9 V max at IF = 10 mA, and the device is rated for 500 mW total power dissipation. |

## Key specifications

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

## CAD (KiCad official)

- Symbol: `MM1Z5B1`
- Footprint: `Diode_SMD:D_SOD-123F`
- 3D model: SOD-123 (KiCad packages3D, STEP)
- 3D model files: `mm1z5b1-etched.step` / `mm1z5b1-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mm1z5b1.step` / `mm1z5b1.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/8586185561010262016) (3 pp, sha256 `64f0ed49c5daf8d8`, retrieved 2026-10-09, 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/mm1z5b1-datasheet.pdf)